Scrape the gills out of each mushroom. Brush olive oil over each mushroom (top and bottom) and season with salt and pepper. Arrange mushrooms, gill-side up, on a baking sheet.
Bake in the preheated oven until tender, about 7 minutes.
Combine ground beef, chorizo, onion, bacon, egg, garlic, cilantro, 1/2 teaspoon salt, 1/2 teaspoon black pepper, garlic powder, onion powder, and chili powder in a large bowl just until mixed; shape into 8 patties. Place a patty on top of each mushroom.
Bake in the preheated oven until burgers are fully cooked, about 20 minutes. An instant-read thermometer inserted into the center should read at least 160 degrees F (70 degrees C).