You can bake this or broil it. It'll take a little longer to bake it at a lower temperature.
Ina. medium bowl mix ricotta cheese with egg, oregano, garlic salt and mix well.
Add 1 1/2 cups mozzarella cheese (reserving the remaining 1/2 for the top) and stir to combine.
Place the minute into 1- 6 dishes oven-safe dishes. This will make 6 appetizer size dishes, or place it in what size you prefer or 1 dish but if only using one dish make sure the mixture will not be too deep, you'll want it to heat quickly, evenly about 8" round will be good.
Spread the cheese mixture in the dishes. Place a couple of tablespoons of sauce on top and spread smooth, then top with additional mozzarella cheese.
Preheat oven to 400° or high broil.
Place the dishes in the middle of the oven for 5-10 minutes or until the mixture is hot, then place under the broiler closer to brown the cheese for a minute or two.
Toast the sliced bread on the oven rack or pizza screen so it's all toasted on both sides. You can toss the bread with some oil if desired before toasting.
Serve warm, dip the bread into the hot cheese dip and enjoy.