Preheat the oven to 350°F (175°C). Grease the baking pan.

In a mixing bowl, whisk together the sugar and melted butter until smooth.

Add the eggs and vanilla extract, and mix until well combined.

Sift in the cocoa powder, flour, salt, and baking powder. Stir until just combined.

Pour the brownie batter into the prepared baking pan and spread evenly.

Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.

While the brownies are baking, melt the white chocolate chips using a double boiler.

Once melted, remove from heat and stir in the peppermint extract.

Pour the melted white chocolate over the baked brownies and spread evenly.

Sprinkle the crushed peppermint candies on top of the melted chocolate.

Let the brownies cool completely before cutting into squares.