Step 1

For the dough: Mix all ingredients just until combined. Do not over mix. Divide in half.

Step 2

Spread half on the bottom of your baking dish. Bake at 350 degrees F in a preheated oven for about 10-15 minutes. Cool slightly.

Step 3

For the filling: Whisk egg whites until stiff peaks are formed.

Step 4

In a large bowl, mix yogurt with sour cream, sugar, lemon zest, vanilla, and flour. Gently fold in egg whites.

Step 5

Pour filling on the baked dough. Take the other half of the dough and crumble it over the filling.

Step 6

Bake for about 30 more minutes until top is golden. Check with toothpick for whether the filling in the middle is cooked.

Step 7

Cool to room temperature and leave in the refrigerator for at least 2 hours. Serve chilled.