Preheat the oven to 375°F (190°C) and line baking sheets with parchment paper.

In a stand mixer, combine softened butter, light brown sugar, granulated sugar, and vanilla extract. Beat until light and fluffy for about 3-4 minutes. Add eggs one at a time, mixing well after each.

In a separate bowl, whisk flour, cocoa powder, baking soda, and salt. Gradually blend the dry ingredients into the wet mixture until fully combined.

Drop tablespoons of cookie dough onto prepared sheets, spacing them 2 inches apart. Aim for about 12 cookies per sheet.

Bake for 8 to 10 minutes. The edges should be set, but centers soft and slightly underbaked. Cool on a wire rack.

In a saucepan over medium heat, combine evaporated milk, sugar, egg yolks, butter, and vanilla. Stir continuously until thick and golden, about 11-12 minutes. Fold in coconut and chopped pecans.

Spread the pecan-coconut frosting over cooled cookies. Optionally, drizzle with melted chocolate candy coating. Refrigerate briefly to set the frosting.