Start by placing a rack in the center of your oven and preheating it to 375 degrees F. It's important to get the oven nice and hot for even baking. While that's happening, coat a 9x13-inch pan with nonstick spray to ensure your cake releases easily.
Next, dissolve the lemon gelatin in the boiling water. You can do this by measuring the water into a large measuring cup and stirring in the gelatin until fully dissolved. Let it cool to room temperature while you continue with the next steps.
In a medium mixing bowl, or using a stand mixer with the paddle attachment, beat together the canola oil, applesauce, and eggs until fully combined. This mixture should look smooth and slightly frothy.
Now, beat in the cooled gelatin mixture. It’s important to add it after it has cooled, as hot gelatin could cook the eggs. Mix until everything is well incorporated.
Reduce the mixer speed to low and slowly add in the yellow cake mix. Stop mixing as soon as you no longer see dry ingredients; over-mixing can lead to a denser cake.
Pour the batter into the prepared pan, using a spatula to spread it evenly. This helps to ensure that it bakes uniformly and rises properly.
Bake the cake for about 25 to 30 minutes. You'll know it's done when the top springs back lightly when touched, and a toothpick inserted into the center comes out clean, with just a few moist crumbs clinging to it.
While the cake is baking, prepare the glaze by whisking together the powdered sugar and lemon juice in a medium bowl until smooth. This glaze will beautifully complement the cake.
As soon as the cake is out of the oven, use the tines of a fork to poke holes all over the top. This step is crucial; it allows the glaze to seep into the cake, ensuring every piece has that delightful lemon goodness.
Pour the glaze slowly and evenly over the warm cake, allowing it to drip down into the holes. Once it's fully coated, let the cake cool to room temperature. Enjoy it warm or chilled, topped with fresh berries and whipped cream.
