Line a 15 X 10 X 1 baking pan with waxed paper. Prepare cake according to package directions. Pour batter into prepared pan. Bake at 350 degrees for 15-20 minutes or until cake springs back when lightly touched. Cool for 5 minutes. Turn cake onto a kitchen towel dusted with confectioners' sugar. Gently peel off waxed paper. Roll up jelly-roll style in the towel, starting with a short side. Cool on a wire rack.
In a bowl, whisk the yogurt, pudding mix and food coloring if desired. Fold in whipped topping. Unroll cake; spread filling evenly over cake to within 1/2 inc. of edges. Roll up. Cover and freeze. Remove from freezer 30 minutes before slicing. Yield: 10 servings.
This is very good. It looks nice garnished with sliced strawberries. You might also dust it with powdered sugar.