Preheat oven to 350°F and spray 9x13 baking dish with nonstick cooking spray.
In a medium saucepan over medium heat, whisk together the corn syrup, brown sugar, eggs, butter, and vanilla. Stir continuously until mixture thickens and coats the back of a spoon, ~10 minutes. Stir in chopped pecans and cook for another 3-5 minutes. * Then set aside.
1 cup light corn syrup, 1 cup brown sugar, 3 large eggs, ¼ cup unsalted butter, 2 teaspoon vanilla extract, 2 cups Pecans – roughly chopped
In a microwave safe dish melt the butter. Microwave for 30 seconds, stir, and repeat until the butter is completely melted.
¾ cup + 3 tbs unsalted butter
Stir cocoa powder into melted butter making sure there are no clumps. Set aside.
¾ cup cocoa powder
While butter mixture is cooling, in a separate small bowl combine the flour, baking powder, and salt. Set aside.
1 cup all-purpose flour, ½ teaspoon baking powder, ¼ teaspoon salt
In a stand mixer, or using a hand mixer, mix together the butter mixture (it’s okay if it’s still warm), sugar, espresso powder, and vanilla. Then add the eggs one at a time, letting each egg become fully incorporated into the batter before adding the next.
2 cups sugar, 1 teaspoon espresso powder*, 4 large eggs, 1 teaspoon vanilla
By hand, with a large rubber spatula or mixing spoon, fold in the flour mixture. Folding in the flour will help the brownie batter keep the air in it.
Fold in the chocolate chips.
1 cup milk chocolate chips*
Pour into the prepared baking dish and bake for 15 minutes (brownies will not be done yet!)
After 15 minutes, remove half-baked brownies from oven, gently spread pecan pie filling over brownies and return to oven. Bake for another 20-25 minutes, or until a toothpick comes out clean
Allow brownies to cool completely before cutting!