Preheat the oven to 350 F. Line a 12 cup muffin pan with paper liners. In a large bowl, whisk together melted butter, brown sugar, and eggs until smooth.
Add in the flour, salt, and baking powder, and mix until smooth. Fold in the sprinkles and chocolate chips.
Evenly divide the batter between the paper liners. Bake for 12-15 minutes.