Step 1: Preheat your oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan thoroughly.
Step 2: Prepare the white cake batter according to the package instructions. Pour the prepared batter evenly into the baking pan.
Step 3: Bake for 25-30 minutes, or until a wooden toothpick inserted into the center comes out clean. Let the cake cool in the pan for exactly 10 minutes.
Step 4: While the cake is still warm, use the handle of a wooden spoon or a round dowel to poke holes across the entire surface of the cake, spaced about an inch apart. Be careful not to poke all the way through to the bottom.
Step 5: In two separate bowls, mix each gelatin flavor with 1 cup of boiling water. Stir each until the gelatin is fully dissolved.
Step 6: Carefully pour the liquid gelatin into the holes, alternating colors to create a beautiful pastel pattern inside the cake. You can use a small spoon or squeeze bottle for more precision.
Step 7: Refrigerate the cake for at least 4 hours (or preferably overnight) to allow the gelatin to fully set and for the cake to become perfectly moist.
Step 8: Once chilled, spread the thawed whipped topping evenly over the cold cake. Decorate with your favorite Easter candies and sprinkles before serving. Keep refrigerated.