Preheat the oven to 350 F. Line a 12-cup muffin pan with paper liners. In a large bowl, whisk together flour, sugar, cocoa powder, salt, and baking soda. Add in melted butter, eggs, and vanilla extract, whisk until smooth.
Evenly divide the brownie batter between the prepared muffin cups. In a medium bowl, whisk together flour, salt, and baking soda. In a large bowl, combine butter with both sugars until fluffy. Add in egg and vanilla extract, mix until smooth.
Add in the flour mixture, and mix until it is fully combined. Fold in the chocolate chips. Evenly divide the cookie dough over the brownie batter in the muffin cups. Bake for 15-20 minutes.
