Andes Mint Brownies

1 1/2 cups butter, melted
1 cup unsweetened cocoa powder
3 cups granulated sugar
4 eggs
2 cups flour
1/2 tsp salt
1 tsp vanilla
3 (4.67 oz) boxes individually wrapped Andes mints

Preheat oven to 350.
Line a 13x9 inch baking dish with aluminum foil, and lightly spray with baking spray.
In a medium bowl, combine the butter and cocoa powder, stirring completely.
Set the chocolate mixture aside. In the bowl of a stand mixer, beat the sugar and eggs until fluffy.
Slowly beat in the chocolate mixture.
Add in the flour, salt, and vanilla, beating until thoroughly combined.
Spread half of the brownie mixture in the pan, distributing evenly.
Place the mints in an even layer, side-by-side, completely covering the brownie mixture.
Spread the remaining brownie mixture over the mints, covering completely.
Bake for 35-40 minutes, or until a toothpick inserted in the top (not all the way through the mint layer) comes out clean.
Cool completely, cut in small squares.