Heat oven to 350°F. In medium bowl, mix mashed sweet potatoes, sweetened condensed milk, pumpkin pie spice and egg.
Separate dough into 5 biscuits. Cut each biscuit in half. Press 1 dough half in each of 10 ungreased regular-size muffin cups, firmly pressing dough to cover bottom and side, forming 1/4-inch rim over edge of cup. Spoon about 2 tablespoons sweet potato mixture into each cup.
Bake 20 to 25 minutes or until edges of dough are golden brown and filling is set. Cool in pan 1 minute; remove to cooling rack. Cool about 15 minutes. Serve warm with dollop of whipped topping.