Yields: 9 servings Prep time: 25 minutes Bake time: 28-33 minutes
Ingredients
- For the Cake:
- Approx. 12 oz (about 2 ½ cups / 340g) White Cake Mix (measured from a standard box)
- Approx. 2 teaspoons (about ¾ of a 0.3 oz packet / 6g) Sugar-Free Strawberry Gelatin Mix
- 3 large Egg Whites
- ¼ cup (60 ml) Canola Oil (or other neutral vegetable oil)
- ¾ cup (approx. 120g) frozen unsweetened strawberries, thawed (retain juice)
- 6 tablespoons (90 ml) Water
- 1 teaspoon finely grated lemon zest (optional)
- 1-2 drops pink or red food coloring (optional)
- For the Strawberry Frosting:
- ¼ cup (4 tbsp / 57g) unsalted butter, softened
- 2 generous tablespoons mashed thawed strawberries with juice (reserved from the ¾ cup above)
- 1 ¾ cups (approx. 210g) confectioners’ sugar (powdered/icing sugar)
- Extra confectioners’ sugar or 1-2 tsp milk/cream, if needed for consistency
- 1 drop pink or red food coloring (optional)
Instructions
- Preheat and Prepare Pan: Preheat oven to 350°F (175°C). Grease and flour a 9×13 inch baking pan, or line it with parchment paper, leaving an overhang for easy removal.
- Mash Strawberries: Place the thawed strawberries and their juice in a small bowl. Mash them well with a fork or briefly pulse in a food processor. Measure out and reserve 2 generous tablespoons of this strawberry mash for the frosting.
- Combine Dry Ingredients: In a large bowl, whisk together the measured cake mix and the measured strawberry gelatin powder.
- Mix the Batter: Add the egg whites and canola oil to the dry ingredients. Beat with an electric mixer on low speed just until combined, then on medium speed for 1-2 minutes until well blended. Add the remaining mashed strawberries (approx. ½ cup + 2 tbsp), the 6 tablespoons of water, and the optional lemon zest and 1-2 drops of food coloring. Beat on low speed until just combined – do not overmix.
- Bake the Cake: Pour the batter evenly into the prepared 9×13 inch pan. Bake for 28-33 minutes, or until a wooden toothpick inserted into the center comes out clean.
- Cool the Cake: Let the cake cool in the pan on a wire rack for 10-15 minutes. Then, carefully invert it onto the wire rack (or use parchment overhang to lift it out) to cool completely before frosting.
- Make the Frosting: In a medium bowl, beat the softened butter with the reserved 2 tablespoons of mashed strawberries until well combined and creamy. Gradually add the 1 ¾ cups of confectioners’ sugar, beating on low speed initially, then increasing to medium-high speed until the frosting is light, fluffy, and smooth. Beat in the optional drop of food coloring if desired. If the frosting is too thick, beat in milk or cream 1 teaspoon at a time. If it’s too thin, beat in more confectioners’ sugar 1 tablespoon at a time until it reaches a spreadable consistency.
- Frost and Serve: Once the cake is completely cool, spread the strawberry frosting evenly over the top of the cake. Cut into 9 rectangular pieces and serve.
Recipe Notes:
- Measuring the cake mix and gelatin ensures the proportions work for this scaled-down recipe. Using the entire packages would alter the texture.
- The amount of liquid released by the thawed strawberries can vary; the batter should be pourable but not overly thin.
- Ensure the cake is fully cooled before frosting to prevent the frosting from melting.
- Store leftover cake covered at room temperature for up to 2 days, or in the refrigerator for up to 4 days (bring to room temperature before serving for best texture).
Nutritional Information (Per Serving)
(Estimates based on standard nutritional databases for typical white cake mix, sugar-free gelatin, and other ingredients. Actual values may vary based on specific brands and measurement accuracy.)
- Calories: Approx. 345 kcal
- Total Fat: Approx. 18.4 g
- Saturated Fat: Approx. 5 g (Estimate)
- Total Carbohydrates: Approx. 54.6 g
- Dietary Fiber: Approx. 0.5 g (Estimate)
- Total Sugars: Approx. 40 g (Estimate)
- Protein: Approx. 2.8 g
- Sodium: Approx. 250 mg (Estimate)
