Step 1: Prepare the Brownie Layer

1. Preheat the Oven: Start by preheating your oven to 350°F (175°C). Grease a 9-inch pie dish or line it with parchment paper to ensure easy removal later.
2. Melt the Butter: In a medium saucepan, melt the unsalted butter over low heat. Once melted, remove it from the heat and stir in the granulated sugar, eggs, and vanilla extract until the mixture is well combined.
3. Mix Dry Ingredients: In a separate bowl, whisk together the unsweetened cocoa powder, all-purpose flour, salt, and baking powder. This will ensure that the dry ingredients are evenly distributed.
4. Combine Mixtures: Gradually add the dry ingredient mixture to the wet mixture, stirring gently until just combined. Be careful not to overmix, as this can lead to a denser brownie.
5. Spread in Pie Dish: Pour the brownie batter into the prepared pie dish, spreading it evenly across the bottom with a spatula. If you’re using chocolate chips, fold them into the batter at this stage.

Step 2: Prepare the Pecan Pie Layer

1. Mix the Filling: In a large mixing bowl, combine the corn syrup, brown sugar, melted butter, eggs, vanilla extract, and salt. Whisk the mixture until it is smooth and well blended.
2. Add Pecans: Stir in the chopped pecans, ensuring they are evenly coated with the filling mixture. You can also use whole pecans if you prefer a more rustic look.

Step 3: Assemble and Bake

1. Pour Pecan Filling: Carefully pour the pecan filling over the brownie layer in the pie dish. Use a spatula to spread it evenly if necessary.
2. Bake: Place the pie in the preheated oven and bake for about 45-50 minutes. The pecan topping should be set and slightly puffed, while the edges will be firm. The center may still appear a little soft, but it will firm up as it cools.
3. Cool: Once baked, remove the pie from the oven and allow it to cool at room temperature for at least 30 minutes before slicing. This cooling time helps the layers set properly and makes for cleaner slices.