Preheat oven to 350°F. Line a 9- x 13-inch baking sheet with parchment paper and grease well.
In a large bowl, mix evoo, sugar, vanilla, salt, almonds, and lemon zest until just combined. Press crust into and up the side of the lined sheet pan.
Bake at 350°F until lightly browned, about 15 to 20 minutes. Set aside.
In a large bowl whisk together sugar, starch, zest, and salt to break up starch clumps. Add eggs and lemon juice and whisk until smooth.
Gently pour filling into baked crust. Bake at 350°F for 20 to 30 minutes until the center is no longer jiggly.
Cool completely before chilling in the fridge for a few hours or overnight. Slice into bars and garnish with powdered sugar just before serving if desired.