Dissolve yeast and brown sugar in warm water; let sit for 10 minutes.

Stir in salt and olive oil.

Combine yeast mixture with 3 cups of flour.

Knead dough, adding remaining flour gradually until no longer sticky.

Place dough in an oiled bowl, cover, and let rise in a warm place for 1 hour.

Punch down the dough and divide into two equal pieces.

Roll out each piece into a circle, about 1/2 inch thick.

Mix refried beans, taco sauce, and pizza sauce in a bowl.

Preheat oven with pizza stones at 425°F (220°C) for 15 minutes.

Spread sauce mixture on each pizza dough, leaving a small border.

Top with mozzarella, seasoned ground beef, and Colby-Jack cheese.

Transfer pizzas to hot pizza stones using a pizza peel.

Bake for 10-15 minutes, until golden brown and cheese is melted.

Cut into slices and top with lettuce, sour cream, taco sauce, and crushed Doritos (optional).