This pastel rainbow cake recipe is one of the best Easter cake ideas! Above all, this Easter cake recipe tastes incredibly delicious because underneath the rainbow and the chocolate Easter eggs you’ll find a a moist crumble cake with vanilla buttercream on top and a fruity rhubarb filling. A super delicious Easter cake design made easy with these step-by-step instructions. Rhubarb Crumble Cake Since it is one of my Easter cake recipes, I also wanted to keep the taste very spring-like, so I decided to make an easy rhubarb crumble cake for this rainbow cake recipe. A delicious and moist…