Place a rack in middle of oven; preheat to 475° F.

Line a baking sheet with foil and coat with olive oil spray. Arrange tomatoes covering entire surface, okay to overlap. Spray tops with olive oil spray and lightly season with salt and pepper. Roast until tomatoes begin to look dry on top, 25–30 mins. Let cool. Reduce oven temperature to 375° F.

Melt butter and add 1 TBS garlic.

Pulse crackers in a food processor until fine crumbs form. Add eggs and garlic butter and pulse until mixture is the consistency of wet sand. Transfer to springform pan. Press crumbs firmly onto bottom and 1½" up sides of pan. Bake crust until edge is just starting to take on color, 8–10 mins. Transfer pan to a wire rack and let crust cool.

Mix together Taleggio, Parmesan, mayonnaise, garlic, chopped thyme, and pepper. Gently layer half of cheese mixture over bottom of crust. Layer half of tomato slices over and press down to even out layers. Repeat with remaining cheese mixture and tomatoes. Top with shallot slices.

Set pan on a rimmed baking sheet and bake until filling is bubbling vigorously and crust is browned, 60–75 minutes. Transfer to rack and let cool before serving.