In a larger bowl, mix all ingredients until a crumbly dough is formed. Press mixture evenly in a lined parchment 13x9 dish. Bake at 350 for 20 minutes.
Filling
In a large bowl, mix all ingredients well. Pour mixture over crust.
Crumb
Mix ingredients until a crumb is formed. Sprinkle on top of filling then bake for 20-25 minutes. Cool completely and then cut into squares.
Notes
Optional but recommended -Sprinkle with powdered sugar.
Recipe by Domestic Dee at https://domesticdee.com/lemon-crumb-bars/