Brownie Stuffed Cookies

Ingredients

• 1 box brownie mix (plus ingredients called for on box)
• 1 1/2 cups all-purpose flour
• 1/2 teaspoon baking soda
• 1/2 teaspoon salt
• 1/2 cup unsalted butter, softened
• 1/2 cup brown sugar, packed
• 1/4 cup granulated sugar
• 1 large egg
• 1 teaspoon vanilla extract
• 1 cup semi-sweet chocolate chips (plus extra for topping)
• 8 oz white chocolate, chopped
• 1/4 cup heavy cream
• 1/2 cup chocolate chips for drizzling