Quesadilla Salvadoreņa

From Luis.
Ingredients:
3 cups of granulated sugar
4 eggs, separated
1 12-oz can of evaporated milk
2 cups of grated queso seco, queso fresco, or parmesan cheese
3 cups of all-purpose flour, sifted
1 tbsp of baking powder
1 cup of butter, melted
1 tsp of sesame seeds

Preheat oven to 350 F. Line a 13 x 9 pan with parchment paper.
Combine egg yolks and 1/2 cup of evaporated milk in a large bowl and beat at medium speed with an electric mixer. Add cheese and remaining milk little by little, scraping bowl a couple of times. Add flour, baking powder, melted butter, and sugar. Mix well.
In a separate bowl, beat egg whites until stiff peaks form. Fold egg whites into batter. Pour mixture into baking pan. Top with sesame seeds.
Bake for ~50 minutes or until a toothpick inserted near the middle comes out clean. Check at 40 minutes and cover with foil if top is getting overly brown. Remove from oven and allow to cool in pan on a wire rack. Take quesadilla out of pan and cut into squares.