Combine cake mix with the ingredients on the back of the box and bake cake according to the box directions in a large bowl.
Let the cake cool for about 30 minutes, then poke holes with a small wooden spoon or something similar. Poke holes close, but not so close that they blend into each other (about 1 inch between), and only about ¾ of the way down.
Prepare blue Jello in a small bowl or spouted measuring cup by adding 1.5-ounce Jello mixture (half of a small box), followed by ½ cup hot water. Stir until dissolved then add ¼ cup cold water.
Repeat for the red Jello.
Carefully spoon Jello mixtures into alternating holes, pouring one color into each hole. Set in the fridge for at least 2 hours.
Add Cool Whip and any fresh berries desired to the top of the cake when ready to serve.
Prepare and bake cake according to the box directions.
Allow the cake to cool for about 30 minutes, then poke holes with a small wooden spoon or something similar. Poke holes close, but not so close that they blend into each other (about 1 inch between), and only about ¾ of the way down.
Prepare blue Jello in a small bowl or spouted measuring cup by adding 1.5-ounce Jello mixture (half of a small box), followed by ½ cup hot water. Stir until dissolved then add ¼ cup cold water.
Repeat for the red Jello.
Carefully spoon Jello mixtures into alternating holes, pouring one color into each hole. Set in the fridge for at least 2 hours.
Add Cool Whip and any garnishes desired when ready to serve.