Line a 9X9 inch brownie pan with parchment paper and preheat oven to 350F
In a large bowl mix together all of the dry pie dough crumble ingredients. Using your hands mix together and make sure all of the shredded butter is coated with flour.
Add all of the wet ingredients together in a small bowl and whisk. After whisking, pour wet mixture into dry bowl and stir. The mixture should be clumpy and feel like wet sand.
Scoop about 2/3rd's of the pie dough crumble into the prepared pan. Press mixture down using a spatula or the bottom of measuring cup. Be sure to really press down on the corners and sides of the crust. This will help the base be sturdy.
In a bowl mix together the strawberries, rhubarb, sugar, cornstarch, and lemon zest. Pour the mixture over the crust and top it with the remaining 1/3 of the pie dough crumble. Lightly press down.
Place pan in preheated over and bake for 50 minutes. When done, remove from oven and allow to cool for one hour. This is key or the squares will fall apart. It needs time to congeal.. just like a pie! I let mine cool for 1 hour and then popped it in the freezer for 15 minutes. If you can leave it for a couple hours on the counter you should be good to go!
Once cooled, remove from pan and cut into squares! Enjoy!
