Lemon Velvet Sheet Cake is like a long tall glass of lemonade in a sheet pan...tart and tangy and oh so inviting. This easy vintage inspired lemon cake is a potluck classic!
Preheat oven to 350F. Lightly butter and flour a 9x13 pan.
Put the sugar and lemon zest in a food processor and process until they are completely combined and the sugar is pale yellow and fragrant.
Put the lemon sugar in a large mixing bowl and whisk in the eggs, oil, and lemon paste.
Whisk in the lemon juice and sour cream, and get it as smooth as you can, but don't worry about little lumps.
Whisk in the baking soda, baking powder, and salt. Then fold in the flours. Note: the batter will be somewhat lumpy.
Pour the batter into the preapred pan and bake for 30-33 minutes just until the cake is firm to the touch and is starting to turn golden.
Cool for 15 minutes before spreading the glaze over the entire surface.
glaze
Whisk or process your sugar and lemon juice together until smooth. Add a bit more lemon juice if you feel that your glaze is too thick.
Spread evenly over the warm (but not hot) cake. Let cool before slicing. Note: if you want very sharp slices, make sure you let the glaze completely harden before you cut into it.