• Preheat your oven to 350°F (175°C). Grease a muffin tin or line it with paper liners.
• Brownie batter: In a large bowl, whisk together melted butter, granulated sugar, and brown sugar until smooth. Add eggs one at a time, beating well after each addition. Stir in vanilla extract.
• Combine dry ingredients: In a separate bowl, sift together flour, cocoa powder, and salt. Gradually add to wet ingredients, mixing until just combined. Fold in chocolate chunks.
• Spoon brownie batter into prepared muffin tin, filling each cup about halfway.
• Pecan pie filling: In another bowl, mix together brown sugar, corn syrup, melted butter, eggs, and vanilla extract until well combined. Stir in chopped pecans.
• Top brownie batter with a spoonful of pecan pie filling, ensuring each cup is well-filled but not overflowing.
• Bake for 25-30 minutes, or until a toothpick inserted into the center comes out mostly clean.
• Cool in the tin for 10 minutes before transferring to a wire rack to cool completely.

Notes

• Use room temperature eggs for a smoother batter.
• Don’t overmix the brownie batter to keep it fudgy.
• Toast pecans slightly before adding to the filling for extra depth of flavor.