Jiggly Jello Cake

Creamy, colorful, and delightfully wobbly — this Rainbow Jello Jiggly Cake is a nostalgic showstopper made with seven vibrant layers and a smooth condensed milk center. It’s a make-ahead dessert that slices beautifully and brings instant joy to any gathering.

Yield

1 (9 × 13 inch) layered gelatin cake

Prep Time

45 minutes active time
4–6 hours chilling time (overnight recommended)

Ingredients

For the Gelatin Layers
7 small boxes (3 oz / 85 g each) regular gelatin
Colors: red, orange, yellow, green, blue, purple, plus one additional color if desired
7 cups boiling water (1 cup per box)
3½ cups cold water (½ cup per box)

For the Condensed Milk Layer
2 packets unflavored gelatin
1½ cups boiling water
1½ cups sweetened condensed milk

Instructions

Lightly grease a 9 × 13 inch glass baking dish with nonstick spray or a thin layer of oil. Set aside.

Prepare the gelatin layers one color at a time. In a mixing bowl, dissolve one box of gelatin in 1 cup boiling water, stirring until completely smooth with no visible granules. Add ½ cup cold water and stir gently to combine.

Measure out about ¾ cup of the prepared gelatin mixture and pour it evenly into the prepared dish. Refrigerate for 20–30 minutes, or until the layer is set to the touch but still slightly tacky.

Repeat this process with each color, stacking the layers in rainbow order. After the third color layer has set, pause to prepare the condensed milk layer.

In a bowl, dissolve the unflavored gelatin in 1½ cups boiling water, whisking until fully dissolved. Stir in the sweetened condensed milk until smooth. Let the mixture cool for about 10 minutes so it is warm but not hot.

Gently pour the condensed milk layer over the set gelatin layer. Return the dish to the refrigerator and chill for 30–40 minutes, or until the cream layer is fully set.

Once firm, continue layering the remaining gelatin colors using the same method, allowing each layer to set before adding the next.

After all layers are complete, refrigerate the cake for at least 4 hours, preferably overnight, to ensure everything is fully set.

Slicing and Serving

For clean, sharp slices, dip a sharp knife in hot water and wipe dry before cutting. Clean the knife between each cut. Serve chilled for the best texture and jiggle.

Kitchen Tips

• Let each gelatin layer cool slightly before pouring to prevent melting the layer below.
• Thin layers create the best jiggle and crisp color separation.
• Glass baking dishes set more evenly than metal.
• Don’t rush the chilling time — patience ensures sharp, vibrant layers.

Nutritional Information (approx. per serving)

Calories 180, Protein 3g, Fat 2g, Carbs 38g, Fiber 0g, Sugars 34g, Sodium 120mg