Preheat the oven to 350 F. In a medium bowl, whisk together flour, salt, and baking soda. In another large bowl, combine butter with sugar until fluffy. Add in the egg and vanilla extract, and mix until smooth.
Add in the flour mixture, and mix until the flour is fully combined. In a large bowl, whisk together flour, sugar, cocoa powder, salt, and baking soda. Add in eggs, melted butter, and vanilla extract. Mix until smooth.
Pour the brownie batter into a greased 8-inch square baking dish. Top with the sugar cookie dough. Bake for 25-30 minutes.
