Spread the sliced tomatoes over several layers of paper towels and sprinkle with salt. Let them drain for 30 minutes to draw out excess moisture—this ensures the crust stays crisp rather than soggy.

Whisk a portion of the oil and the minced garlic together in a small bowl. In a separate bowl, stir together the Parmesan, ricotta, mozzarella, and the remaining oil, then season with salt and pepper until well combined.

Adjust the oven rack to the middle position and heat the oven to 425°F. Spread the ricotta mixture evenly across the bottom of the tart shell.

Blot the tops of the tomatoes dry with paper towels, then shingle them in overlapping concentric circles over the cheese. Drizzle the garlic-oil mixture evenly over the tomatoes.

Bake the tart on a rimmed baking sheet until the cheese is bubbling and the tomatoes look slightly wilted, about 20 to 25 minutes, rotating the pan halfway through for even browning.

Cool the tart on the baking sheet for at least 10 minutes to allow the filling to set. Remove the outer ring, slide the tart onto a platter, and finish with a sprinkle of fresh basil before serving.