Heat oven to 350°F. Bake biscuits as directed on can.
Meanwhile, place powdered sugar in brown paper lunch bag or large resealable food-storage plastic bag.
When doughnuts are hot from the oven, brush with butter. Place in paper bag, and shake until completely coated in powdered sugar. Transfer to cooling rack.
Place strawberry jam in decorating bag fitted with tip. Insert tip inside of each biscuit; squeeze small amount of jam into center.