Cake Mix Cookie Bars

Easy Chocolate Chip Cake Mix Cookie Bars

The smell of bubbling butter and warm vanilla hitting the oven air is basically a hug in scent form. I remember one rainy Tuesday when my kids were practically climbing the walls and I realized I had exactly zero energy to pull out the flour, sugar, and baking soda.

I found a lonely box of yellow cake mix in the back of the pantry and decided to see if I could turn it into something thicker and more substantial than a standard cupcake.

I started experimenting with different fats and binders, eventually stumbling upon the "secret sauce" of adding a box of pudding mix. The first time I pulled these out of the oven, the edges were crackling and the center was still slightly molten from the chocolate chips.

We didn't even wait for them to cool properly before we were digging in with spoons, laughing about how much better these were than the actual cake the box was intended for.

It's one of those recipes that feels like a cheat code for everyday life. You get all the flavor of a from scratch bakery bar without the sink full of measuring cups. Whether you're a seasoned pro or just someone who wants a sweet treat without the stress, this is the one that actually works every single time.

We've made these for everything from school events to late night movie marathons, and they never last more than an hour on the counter.

Why This Recipe Works

• Starch Modification: The cornstarch in the instant pudding mix interferes with gluten development, ensuring the bars stay tender rather than becoming bread like.
• Fat Emulsification: Using melted butter instead of oil provides a richer flavor and a more cohesive, fudgy crumb that doesn't feel greasy on the palate.
• Maillard Reaction: The high sugar content in the cake mix reacts with the proteins in the eggs, creating those coveted golden brown, crispy edges.

Right then, picking the right thickness is the first step to success. If you like them thin and crispy, go for a larger pan, but for that classic chewy center, stick to the standard 9x13 inch (23x33 cm) dimensions.

Essential Component Analysis

Choosing high-quality fats makes a huge difference here. I always tell my friends that if you use a cheap, watery butter, you might end up with a bit of a puddle. Stick to a solid brand with a high fat content for the best results.

Ingredients And Simple Swaps

To get started, you'll need a few pantry staples. This mix is incredibly forgiving, so don't be afraid to tweak it based on what you have in the cupboard.

• 1 box (432g) Yellow or White Cake Mix
  • Substitute: Chocolate cake mix for a double cocoa version.
  • Why this? Provides the pre measured leavening and flour base needed for structure.
• 1 small box (96g) Instant Vanilla Pudding Mix (Dry)
  • Substitute: Butterscotch or chocolate pudding mix.
  • Why this? The extra starch creates a velvety, fudgy texture that avoids being "cakey."
• 112g (1/2 cup) Unsalted Butter, melted
  • Substitute: Refined coconut oil (melted).
  • Why this? Adds essential richness and helps create the crisp, golden exterior.
• 2 large Eggs
  • Substitute: 1/2 cup unsweetened applesauce (yields a denser, softer bar).
  • Why this? Acts as the primary binder to hold the crumb together.
• 255g (1 1/2 cups) Semi sweet chocolate chips
  • Substitute: Peanut butter chips or chopped walnuts.
  • Why this? Provides pockets of melted sweetness and textural contrast.
• 1/2 tsp Sea salt
  • Substitute: Flaky Maldon salt for the top.
  • Why this? Balances the intense sweetness of the cake and pudding mixes.

I actually picked up some of these tricks from The Secret CAKE recipe which goes deep into how to make boxed stuff taste like it came from a high end bakery.

step-by-step Baking Guide

1. Preheat your oven to 350°F (175°C). Note: A fully heated oven ensures the bars start lifting immediately.
2. Line a 9x13 inch pan with parchment paper. Leave an overhang so you can lift the bars out easily later.
3. Whisk the dry ingredients. Combine the 432g cake mix and 96g pudding mix in a large bowl. Look for any large lumps and break them down.
4. Incorporate the liquids. Pour in the 112g melted butter and add the 2 eggs. Note: Don't overmix, just stir until no dry streaks remain.
5. Fold in the texture. Gently stir in the 255g chocolate chips and 1/2 tsp sea salt until evenly distributed.
6. Press into the pan. The dough will be thick and sticky, so use a spatula or lightly greased hands to spread it to the corners.
7. Bake for 20 minutes. Watch the oven until the top is golden and crackling but the center still has a tiny bit of "give."
8. Check for doneness. A toothpick should come out with a few moist crumbs, not wet batter.
9. Cool in the pan. Let them sit for at least 15 minutes until firm enough to slice.
10. Lift and cut. Use the parchment handles to move the block to a cutting board and slice into 16 even squares.

Fixing Common Baking Problems

Preventing Dry Crumbly Bars

If your bars are falling apart like sand, you likely overbaked them or used too much dry mix. Cake mix brands can vary slightly in weight, so if yours is larger than 15.25oz (432g), add an extra tablespoon of melted butter. Also, remember that these continue to cook in the hot pan after you pull them out.

If they look "done" in the oven, they might be overdone by the time they cool.

Fixing A Greasy Bottom

Sometimes the butter can separate if it was too hot when you added the eggs. This creates a slick layer on the bottom of the pan. Next time, let the butter cool for 5 minutes before mixing. If it happens now, just blot the bottom of the bars with a paper towel after they cool.

It doesn't ruin the flavor, just makes them a bit messy to handle.

Common Mistakes Checklist

• ✓ Using "Cook and Serve" pudding instead of Instant (it won't set correctly).
• ✓ Forgetting to line the pan - these bars are sticky and will cling to the metal.
• ✓ Overmixing the batter until it's tough and bread like.
• ✓ Cutting them while they are still piping hot (they will fall apart).
• ✓ Using cold eggs, which can cause the melted butter to seize up.

Trust me, I've made the "wrong pudding" mistake before and it turned into a gooey mess that we had to eat with spoons. Still tasty, but definitely not a "bar." If you want something even faster for one person, check out The Speedy Pudd recipe for those urgent sugar cravings.

Adjusting The Recipe Size

If you want to cut this recipe in half, use an 8x8 inch square pan. Since the recipe calls for 2 eggs, just beat them together in a small bowl and use exactly half of the liquid by weight or volume. Reduce the baking time by about 5 minutes, but keep a close eye on those edges.

For a big party, you can double the ingredients and use a large rimmed baking sheet (half sheet pan). When doubling, don't double the salt - go for 3/4 tsp instead of a full teaspoon to keep the balance right.

The bake time usually stays about the same because the surface area is larger, but you might need an extra 2 or 3 minutes.

Baking Facts Versus Fiction

One major myth is that you need to follow the instructions on the back of the cake mix box. Ignore them! Those instructions are designed for a light, airy cake. By drastically reducing the liquid and changing the fat source, we are intentionally breaking those rules to create a dense cookie structure.

Another misconception is that you can't use a sugar-free cake mix. You actually can, but the texture will be slightly more brittle. Sugar acts as a liquid when it melts, so if you go sugar-free, you might need an extra tablespoon of water to help the dough come together.

Storage And Kitchen Efficiency

These bars are the kings of longevity. You can keep them in an airtight container at room temperature for up to 4 days. If you find they are getting a bit firm, a 10 second zap in the microwave brings back that "just out of the oven" softness.

In the fridge, they'll last about a week, though they do get quite dense when cold.

For the zero waste enthusiasts, don't throw away the edge pieces if they get too crunchy! Crumble them up and use them as a topping for vanilla ice cream or mix them into a milkshake. You can also freeze the baked bars for up to 3 months.

I like to wrap them individually in plastic wrap so I can grab one whenever the craving hits. It's way better than buying those pre packaged snacks from the store.

If you ever find yourself with half a box of mix left over, you can actually use it to thicken up a fruit cobbler or even stir a spoonful into your morning oatmeal for a "cake batter" treat. We don't waste anything in this kitchen!