Preheat your oven to 350°F (175°C) and line a 9x13-inch baking pan with parchment paper, leaving some overhang. In a medium saucepan, melt the unsalted butter over low heat. Stir in the granulated sugar until smooth and shiny. Remove from heat and cool slightly before whisking in the eggs and vanilla extract until fully combined.

In a separate bowl, sift together the all-purpose flour, cocoa powder, baking powder, and salt. Gradually add the dry mixture to the wet ingredients, gently folding with a rubber spatula.

Pour the brownie batter into your prepared baking pan, spreading it evenly. Bake for 30–35 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.

Remove the brownies from the oven and cool in the pan for about 15–20 minutes, then lift using the parchment overhang onto a wire rack to cool completely.

Cut the cooled brownies into squares. Melt your favorite colors of candy melts in separate bowls. Drizzle the melted candy over each brownie to resemble ribbons and finish with mini candy bows or holiday sprinkles.

Let the decorated brownies sit at room temperature until the candy melts harden, about 15–30 minutes.