Instructions:
- Preheat oven to 350°F (175°C). Grease and flour two 9-inch round cake pans, or line bottoms with parchment paper rounds.
- In a large bowl, whisk together flour, sugar, cocoa powder, baking soda, baking powder, and salt until thoroughly combined.
- In a separate bowl, whisk eggs, buttermilk, oil, and vanilla extract until smooth.
- Gradually add the wet mixture to the dry mixture, mixing on low speed or by hand until just combined. Do not overmix.
- Slowly stream in the hot coffee while mixing gently until the batter is smooth and quite thin. Fold in the chocolate chips.
- Divide batter evenly between the two prepared pans.
- Prepare Topping: In a medium saucepan, melt the butter. Stir in the brown sugar, heavy cream, and vanilla until smooth. Remove from heat and stir in the chopped pecans.
- Carefully spoon the pecan mixture evenly over the top of the batter in both cake pans. Do not stir it in; let it sit directly on top.
- Bake for 45–55 minutes, or until a wooden skewer inserted into the centre of the cake (avoiding the topping) comes out with moist crumbs attached.
- Allow cakes to cool in pans on a wire rack for 15 minutes. Invert the cakes onto the rack, peel off the parchment, and allow them to cool completely before assembling.
- Assemble the cake by placing one layer (pecan-side up) on a serving plate, topping it with the second layer (pecan-side up). Serve as is.