Combine flour, baking powder, garlic powder, onion powder, and salt in a bowl. Stir together. Add greek yogurt and egg, and either by hand or using a stand mixer with a dough hook attachment, mix until your dough is uniform. Flour the outside of the dough, as well as your surface and rolling pin, as the dough will be sticky.
Line 9×13 baking sheet with parchment paper, silicone baking mats, or spray VERY well with cooking spray. Using a rolling pin, roll your dough out until it mostly fills the size of the baking sheet. Carefully transfer dough to baking sheet, and continue to roll/spread it until it roughly fills out the sheet. It’s ok if it’s not perfect!
Spray with cooking spray and bake for ~18 minutes, until just lightly turning golden.
Toppings
Spread 1/2 cup of cheese over crust. Add 1/2 of sauerkraut and 1/2 of roast beef over cheese, leaving crust exposed. Layer on another 1/2 cup of the cheese, then the rest of roast beef, and sauerkraut. Top with remaining 1/2 cup of cheese. Bake 8-10 minutes, until cheese is fully melted.
Dressing
Combine all ingredients for Healthier Thousand Island in a bowl and mix well. Taste and adjust seasonings as desired. Once pizza is removed from oven, let cool slightly and dollop dressing all over the pizza. Cut into 10 slices an enjoy!
Store any leftovers in an airtight container in the fridge (store dressing separately). Reheat in the oven or air fry at 370 for 5 minutes to crisp up.