Set a large skillet over medium-high heat with 1 tablespoon olive oil. Once hot, add the sausage remove from the casing. Being breaking it down with a wooden spoon and cook until browned.
Transfer to a plate using a slotted spoon. Return the skillet to the heat and add the remaining oil and the cherry tomatoes. Season with 1/4 teaspoon each salt, pepper, and Italian seasoning. Cook until the tomatoes have softened and are starting to burst, about 10 minutes.
In a medium bowl, stir to combine the ricotta, basil, lemon, Parmesan and the remaining salt, pepper and Italian seasoning. In another medium bowl, stir butter and garlic until well combined.
To assemble the sandwiches, lay out 4 bread slices in a single layer. Brush the bread with 3 tablespoons of the softened garlic butter, then turn the bread over. Top with 1/4 cup mozzarella, then spread over the ricotta. Top with the Italian sausage, tomatoes and another 1/4 cup mozzarella. Top each with a slice of bread and brush with remaining butter.
Heat a skillet or griddle over moderate heat. Working in batches, cook sandwiches until bread is golden and crisp and cheese has melted, about 3 minutes per side. Transfer to a cutting board and cook the remaining sandwiches. Cut each in half and serve with marinara on the side for dipping.