Step 1

Place a rack in middle of oven; preheat to 475°F. Arrange tomatoes on a rimmed baking sheet, covering entire surface (it’s okay if they overlap). Drizzle with oil; season with salt and pepper. Roast until tomatoes begin to look dry on top, 25–30 minutes. Let cool.

Step 2

Meanwhile, cook garlic and butter in a small saucepan over medium-low heat, swirling often, until butter foams and milk solids turn golden, 5–7 minutes. Strain garlic butter through a fine-mesh sieve into a heatproof measuring cup; transfer garlic and toasty bits to a cutting board. Finely chop and set aside.

Step 3

Reduce oven temperature to 375°F. Pulse crackers and ¼ tsp. salt in a food processor until fine crumbs form (you should have about 2 cups). Add eggs and 6 Tbsp. garlic butter and pulse until mixture is the consistency of wet sand; set remaining garlic butter aside. Transfer to springform pan. Using a flat-bottomed measuring cup, press crumbs firmly onto bottom and 1½" up sides of pan. Bake crust until edge is just starting to take on color, 8–10 minutes. Transfer pan to a wire rack and let crust cool.

Step 4

Mix Taleggio, Parmesan, mayonnaise, chopped thyme, remaining ½ tsp. salt, remaining ¼ tsp. pepper, and reserved chopped garlic in a medium bowl. Gently dollop half of cheese mixture over bottom of crust, then spread into an even layer with an offset spatula (don’t press too hard or you will break the crust). Layer half of tomato slices over and press down to even out layers. Repeat with remaining cheese mixture and tomatoes. Brush remaining garlic butter over tomatoes. Top with shallot and thyme leaves.

Step 5

Set pan on a rimmed baking sheet and bake pie until filling is bubbling vigorously and crust is browned, 60–75 minutes. Transfer to rack and let cool 1 hour before serving.

Step 6

Do Ahead: Pie can be made 1 day ahead. Cover loosely and chill.