Preheat the oven to 350 °F. Spray a 9x13 baking dish with non-stick cooking spray. Line the dish with parchment paper and spray again. Set aside.
Brownie layer
In a large glass mixing bowl melt the butter in the microwave. Add the chocolate and stir until melted and smooth. Cool slightly. Add the sugar and vanilla, and slowly drizzle in the eggs, whisk continuously until combined.
Add flour and stir until combined and no flour is visible.
Bake for 25 minutes. Remove the brownie layer from the oven and set aside.
Derby Pecan Pie layer
Mix the brown sugar, corn syrup, butter, eggs and bourbon together until combined.
Add toasted pecans and chocolate chips. Mix together.
Pour the pecan layer on the brownie layer.
Bake for 35 minutes.
Remove from the oven and cool completely.
Store covered in the refrigerator.
Notes
Recipe originator is Jennifer of https://taketwotapas.com/
This recipe was calculated using the exact brands and measurements I used to make this recipe. If you are following a strict diet please note changing anything will cause the nutritional info to change. My calculations are intended as a guide only.