Preheat your oven to 350℉. Fit the pastry shell for pie into a 9-inch deep dish pie pan, pressing it evenly along the bottom and up the sides. Use a fork to gently poke holes throughout the bottom of the crust to prevent air bubbles. Line the shell with parchment paper and fill it with dry beans or pie weights, which keeps the crust from puffing up. Place the pan on the bottom rack of the oven and bake for 10 minutes. Once done, remove the pie crust from the oven and set it aside to cool slightly. Then carefully remove the parchment and pie weights.

If desired, lightly toast the pecan halves in a dry skillet over medium heat for 3-5 minutes, stirring frequently until they smell fragrant and start to deepen in color. Toasting is optional, but it adds a richer, deeper pecan flavor to the pie. Allow the pecans to cool before adding them to the filling. I always recommend this step when you have a few extra minutes because the toasty flavor makes such a difference!

In a large mixing bowl, combine the packed light brown sugar and unsweetened cocoa powder, stirring until fully blended. Add in the eggs, mixing until the batter is even and smooth. Then pour in the sweetened condensed milk and vanilla extract, stirring until all ingredients are thoroughly incorporated and the filling is uniform in color and texture.

Fold the toasted (or untoasted) pecan halves (from Step 2) into the prepared filling from Step 3, making sure all the pecans are evenly coated. Pour the pecan filling into the parbaked pie crust (from Step 1), using a spatula to spread the mixture evenly.

Place the filled pie on the bottom rack of the oven and bake at 350℉ for 25 minutes. After this initial baking period, cover the edges of the crust with foil or a pie shield to prevent over-browning. Bake for an additional 15-20 minutes, watching for the edges to become set while the center retains a slight, Jell-O like wobble when gently shaken. Remove the pie from the oven and let it cool for two hours before serving, or chill in the refrigerator until ready to serve.