Heat 2 inches of canola oil in a pot over medium-high heat.
In a large bowl whisk together the flour, salt, garlic powder, chili powder, pepper, and cornstarch.
Pour beer into the bowl, stir with a fork until combined (this should be the thickness of pancake batter. If the batter is too thick, add a bit of water to thin but the batter should be very thick).
Place a wire rack over a baking sheet, set aside. Add some flour to a separate bowl, set aside.
One at a time add the tomato slices to the flour, dredge to coat. Then add into the batter until well coated, then add to the hot oil. Fry until golden brown on both sides, about 4 minutes per side, then transfer to the wire rack, allow to cool.
Stir together the crema, chipotle pepper, garlic powder, and salt.
Add the fried tomatoes to the buns, top with bacon, chipotle crema, and basil. Serve immediately.