Spray your jelly roll pan lightly with nonstick spray and line with parchment paper. Preheat oven to 350 degrees F.
In a bowl with a hand mixer or in a stand mixer with the whisk attachment, add separated egg whites and beat with lemon juice and salt until they are foamy. Add sugar gradually and continue to beat until they hold soft peaks. Using a rubber spatula, gently fold in cake flour, being careful not to overmix.
Divide batter into three bowls and add desired food coloring to each batch. Stir gently to combine. Then stir all colored batters back into one bowl, folding a few times to create color swirls.
Pour batter onto prepared jelly roll pan. Bake at 350 degrees for 12 minutes until cake springs back in the center. Remove and let cool in the pan for a few minutes.
Cover pan with a second piece of parchment paper and flip the cake over so it comes out of the pan. Then remove the paper from the top of the cake and tightly roll the cake into a spiral. Let cool completely (you can chill in the fridge for faster cooling).
Make frosting by whipping together cream cheese, cream, sugar, and vanilla until creamy and smooth.
When cake is chilled, unroll and spread on a layer of the frosting to cover the entire cake. Top with crushed candies of your choice (I like the chocolate eggs). Roll cake into a tight spiral.
Dust cake with powdered sugar and decorate with candies before slicing and serving!