Drain blueberries, reserving juice; set aside. Grease a 2-quart square baking dish; set aside. Prepare Rich Shortcake dough. On a lightly floured surface, roll dough into an 11x9-inch rectangle. Brush dough with melted butter or margarine. Combine the 2 tablespoons sugar with the cinnamon; sprinkle over dough. Sprinkle with 1 cup of the drained blueberries. Roll up, starting from a short side. Seal seam. Slice roll into nine equal pieces.
In a small saucepan combine the 1/4 cup sugar and the flour. Add remaining blueberries and reserved juice. Cook and stir until thickened and bubbly. Remove from heat; stir in lemon juice. Pour blueberry mixture into prepared dish. Place rolls, cut side down, on top of blueberry mixture. Bake in a 425 degree F oven for 20 minutes or until rolls are golden. If desired, serve warm with vanilla ice cream. Makes 9 servings.
In a medium mixing bowl combine flour, baking powder, sugar, and salt. With a pastry blender, cut in shortening until mixture resembles coarse crumbs. Make a well in the center of mixture. Add milk and egg all at once. Stir just until dough clings together. On a heavily floured surface, coat the dough lightly with flour. Knead the dough gently for 10 to 12 strokes.