Heat oven to 200ºF (93ºC); line a baking sheet with a wire rack and set aside.
Beat eggs together in a large shallow dish or pie plate. Add coconut milk, sugar, cinnamon, vanilla, nutmeg, cardamom and salt.
Preheat a 10 or 12-inch nonstick skillet over medium for 3 minutes. Meanwhile, dip two slices of bread in custard mixture until soaked, about 15 seconds per side.
Add 1 teaspoon olive oil to skillet and swirl to coat. Place soaked bread slices in preheated skillet over medium heat and cook until dark brown and no longer wet, about 3–4 minutes per side.
Transfer French toast slices to prepared sheet and keep warm in oven. Repeat with remaining bread slices, custard mixture, and olive oil until all of the custard has been used.
Serve with desired toppings, such as butter, berries, and maple syrup.