Preheat oven to 350°F.
Grease a 13x9 inch casserole dish with non-stick cooking spray. Set aside.
In the bowl of a stand mixer, beat eggs on high speed using the whisk attachment. Beat eggs until they are light and fluffy, about 2-3 minutes.
Reduce speed and add flour, baking powder, salt and pepper. Mix until well combined and there are no lumps.
On low speed, add cottage cheese, shredded pepper jack cheese and diced jalapeños.
Once mixture is well combined, pour it into the prepared baking dish.
Top with sliced jalapeño peppers if desired.
Bake casserole for 55-65 minutes, or until golden brown along the edges and the center has set and is no longer jiggly when you shake the pan.
Remove casserole from oven and allow it to rest for 10 minutes before cutting into it and serving.