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 the melted butter, eggs, and vanilla extract until smooth.
In a medium bowl, whisk together flour, salt, and baking soda. In a large bowl, combine butter with peanut butter and both granulated and brown sugars until smooth. Add in the egg and vanilla extract, and mix until smooth.
Add in the flour mixture, mix until it is fully combined. Fold in the sprinkles. Evenly divide the brownie batter between the prepared muffin cups. Top with the cookie dough. Bake for 20-25 minutes.
