Creating these Pecan Pie Brownie Bars involves a straightforward process. Follow these steps to make your delicious dessert:

1. Preheat the Oven: Set your oven to 350°F (175°C). Grease a 9×13-inch baking pan.
2. Mix Brownie Base: In a large bowl, combine melted butter and granulated sugar. Mix well until smooth.
3. Add Eggs and Vanilla: Beat in the 4 eggs and 1 teaspoon of vanilla extract until fully incorporated.
4. Mix Dry Ingredients: In another bowl, combine flour, cocoa powder, and salt. Gradually add to the wet mixture, stirring until just blended.
5. Pour in the Pan: Spread the brownie mixture evenly in the prepared baking pan.
6. Prepare Pecan Filling: In a separate bowl, whisk together corn syrup, brown sugar, 3 eggs, and 1 teaspoon vanilla extract until smooth.
7. Add Pecans: Fold in the chopped pecans into the mixture.
8. Layer the Mixtures: Pour the pecan filling over the brownie base, ensuring it spreads evenly.
9. Top with Pecans: Arrange pecan halves on top of the filling for a beautiful presentation.
10. Bake: Place in the oven and bake for 30-35 minutes, or until set. A toothpick inserted should come out clean.
11. Cool: Remove from the oven and allow to cool in the pan for about 30 minutes.
12. Cut into Bars: Once cooled, cut into squares and serve.