Brownie Cookie Dough Sandwiches

INGREDIENTS

Box of brownie mix of your choice (I used a fudge brownie mix which was delicious, but I think a regular mix would be more puffy)

Necessary ingredients listed on box (e.g. eggs, oil, etc)

3 sticks

unsalted butter, at room temperature

3/4 cup

light brown sugar, packed

3 1/2 cups

confectioners’ sugar

1 cup

all-purpose flour

3/4 tsp

salt

3 tbsp

milk

2 1/2 tsp

vanilla extract

1 cup

mini chocolate chips