First things first, ingredients: One yellow or white cake mix, 2 pints of strawberries, a handful of blueberries, 2 small boxes of vanilla instant pudding (or 1 large box), 1 small container of whipped topping (not from an aerosol can).
First bake the yellow cake. I use two 9-inch pans to decrease the baking time but this part really doesn't matter. After the cake is done cut it into small square pieces. While the cake is in the oven cut up the strawberries and make the vanilla pudding according to the directions on the box. Once the pudding is mixed and set, gently fold in a container of whipped topping.
After you have everything baked, mixed, and cut you can then begin the layering process. First start with a layer of cake on the bottom, followed by strawberries and then top with the pudding/whipped topping mixture. Repeat this 3 times. I use a glass trifle dish but you can really use any type of large serving bowl or cake pan; you may need to decrease the number of layers depending on the depth of the dish.