Assemble the dip in a glass casserole dish. Spread the cream cheese–mayonnaise mixture evenly in the bottom of an 8×8-inch or similar-size glass casserole dish, smoothing the top with a spatula so you have a flat, even layer. This will be your creamy base.
Add the bacon layer. Sprinkle the crumbled bacon evenly over the entire surface of the creamy base, making sure you cover all the way to the edges so every scoop gets plenty of bacon. Reserve a small handful if you’d like to sprinkle a little extra on top right before serving.
Top with tomatoes. Scatter the diced, patted-dry tomatoes evenly over the bacon layer. Gently press them down just a bit so they settle into the bacon without getting buried. If you saved any bacon, sprinkle it over the tomatoes
