Ingredients
Equipment
Method
Bake and cool the cake
- Bake the white cake in a 9x13 pan according to package directions. Cool for 15 minutes, until it’s warm rather than hot.
Poke holes
- Use the handle of a wooden spoon to poke holes all over the cake about 1 inch apart. Keep the holes evenly spaced so the Jell-O soaks through consistently.
Soak with strawberry Jell-O
- Dissolve the strawberry Jell-O in 1 cup boiling water, then stir in 1/2 cup cold water. Pour slowly over the left half of the cake so the liquid fills the holes.
Soak with blue Jell-O
- Dissolve the berry blue Jell-O in 1 cup boiling water, then stir in 1/2 cup cold water. Pour over the right half of the cake so red and blue stripes form side-by-side.
Chill
- Refrigerate the cake for at least 2 hours until the Jell-O is fully set inside the cake. Chill until the surface feels firm when gently pressed.
Frost and garnish
- Spread the whipped topping evenly over the top of the chilled cake. Make sure it covers the entire surface for a clean white layer.
Serve
- Decorate with red and blue star sprinkles and fresh strawberries and blueberries before serving. Slice to reveal the vivid red and blue Jell-O stripes soaked into the white cake.
Notes
Pro tip: pour the Jell-O slowly and directly onto the holes to prevent puddles on top. Store covered in the refrigerator for up to 4 days; the texture is best within the first 2 days. Freezing is not recommended because the Jell-O and whipped topping can weep when thawed. For a lighter option, use a reduced-fat whipped topping or homemade whipped cream folded with a thickener to help it hold its shape.
