Prep Your Eggs: Start by placing the eggs in a bowl of warm water for 5-10 minutes to bring them to room temperature. This ensures a fluffier batter. Crack each egg into a small separate bowl first to check for freshness before adding to the main mix.
Mix the Wet Ingredients: In a large mixing bowl, combine the room-temperature eggs, ½ cup warm water, ¾ cup vegetable oil, and the entire box of strawberry Jell-O. Stir until the Jell-O begins to dissolve.
Add Strawberries and Cake Mix: Incorporate the heaping ½ cup of sweetened sliced strawberries (no need to strain them here). Then, pour in the white cake mix. Using an electric mixer on medium speed, beat everything together for exactly 2 minutes. The batter will turn a vibrant pink and become smooth.
Prepare the Baking Pan: Preheat your oven to 350°F (175°C). Spray a 9×13-inch baking pan generously with nonstick cooking spray. Pour the batter into the pan and smooth the top with a spatula for even baking.
Bake to Perfection: Place the pan in the preheated oven and bake for 35-40 minutes. Check doneness by inserting a toothpick into the center – it should come out clean or with just a few moist crumbs. The top will be golden and the center risen.
Cool Completely: Remove the cake from the oven and let it cool in the pan on a wire rack for at least 2 hours. Cooling is crucial to prevent the frosting from melting.
Make the Frosting: While the cake cools, beat the room-temperature salted butter in a mixer until creamy. Gradually add the powdered sugar, mixing on low to avoid a sugar cloud. Strain the remaining sweetened sliced strawberries from the container, pressing out as much juice as possible, and add them to the bowl. Beat until the frosting is smooth and fluffy. If it seems too sweet, add a pinch of salt.
Frost and Chill: Once the cake is fully cooled, spread the strawberry frosting evenly over the top. For the best flavor, chill the Edgars Strawberry Cake in the refrigerator for 30 minutes before serving, or enjoy at room temperature.