Adapted from here
makes 6 large muffins

1/4 cup granulated sugar
teaspoon cinnamon
1 can (16.3 oz) Pillsbury™ Grands! Homestyle refrigerated buttermilk biscuits
1/2 cup firmly packed brown sugar
6 1/2 Tablespoons butter 
(Add a walnuts and raisins if desired..I don't desire!)

Heat oven to 350°F. Lightly grease 6 extra-large muffin pan (or you can do 12 regular muffins with a shorter baking time)  with shortening or cooking spray. Note: do not use liners because they will stick. Mix granulated sugar and cinnamon in a large bowl.

Separate dough into 8 biscuits; and cut each biscuit into 9 pieces. Add pieces to sugar and cinnamon bowl and coat each piece completely. Add 12 pieces to each greased muffin cup, add walnuts and raisins among the biscuit pieces if using.

In small pan, melt the butter and add the brown sugar; once combined pour over biscuit pieces.

Bake approximately 15 minutes or until golden brown and no longer doughy in center. 
Cool in pan 10 minutes. 

Turn upside down or gently lift up with a fork onto serving plate. Serve warm.