For the cake, Preheat oven to 350°. Grease and flour two 8” x 3” round cake pans. In a small bowl, combine sugar and vanilla. In the bowl of a stand mixer, mix together sugar, cake flour, baking powder, and salt. Add butter and mix on medium- low speed for three minutes. In a small mixing bowl, whisk together eggs, sour cream, oil, and vanilla until smooth. Add the egg mixture to the flour mixture and beat on medium speed until combined. Slowly add milk and mix on low speed until combined. Pour cake batter into prepared pans and bake for 35-45 minutes or until a toothpick/cake tester comes out clean. Allow cakes to completely cool.

For the lemon curd, combine egg yolks, lemon juice and sugar in a double boiler, or in a metal bowl over a pot of simmering water. Heat while whisking until mixture starts to thicken. Add butter and whisk until melted. Add in zest. Pour into a heat proof container, cover with plastic wrap to avoid a film developing and refrigerate until cold.

For the blueberry filling, place blueberries in a saucepan with sugar and lemon juice and half the water. Heat on low to medium until sugar is dissolved, the blueberries will look full with juice. In a separate small bowl, add the cornstarch to the remaining water and mix well. Add cornstarch mixture to the blueberries. Cook on low - the mixture will thicken and looks glossy. When thick enough to coat the back of a wooden spoon or spatula, it’s ready! Remove from heat, pour into a mason jar and let cool completely.

To assemble, slice each cake horizontally to make 2 layers - 4 layers in total. Start with a layer of cake, then a layer of blueberry filling, layer of cake, layer of curd, layer of cake, layer of blueberry and then final layer of cake. You can either leave as a naked cake or ice with your favorite vanilla or lemon icing, or for a treat try vanilla swiss meringue icing.