Step 1: Prepare the Brownie Batter
Preheat your oven to 350°F (175°C). Grease a mini muffin tin or line it with mini muffin liners. In a mixing bowl, whisk together melted butter and sugar. Add the eggs and vanilla extract, mixing until smooth. Stir in the flour, cocoa powder, and salt until just combined.
Step 2: Fill the Muffin Tin
Spoon the brownie batter into the prepared mini muffin tin, filling each cup about ¾ full.
Step 3: Make the Pecan Pie Topping
In a saucepan, combine the chopped pecans, brown sugar, butter, and milk. Cook over medium heat, stirring constantly, until the mixture comes to a boil. Remove from heat and stir in the vanilla extract.
Step 4: Assemble and Bake
Spoon a small amount of the pecan mixture over each brownie bite. Bake for 12-15 minutes, or until the edges are set but the centers are still slightly soft.
Step 5: Cool and Garnish
Let the brownie bites cool in the tin for 5 minutes, then transfer to a wire rack to cool completely. Sprinkle with flaky sea salt before serving.