Step 1: Start Heating the Pan
Place a large non-stick skillet or griddle over medium heat. Add the butter or coconut oil and allow it to melt and heat up while you prepare the batter. This ensures the pan is hot and ready the moment your bread is soaked.

Step 2: Create the One-Dish Banana Custard
Find a wide, shallow dish that is large enough to fit a slice of bread. A pie plate or a rimmed dinner plate works perfectly. Place the ripe banana in the dish and use a fork to mash it thoroughly until it’s mostly smooth, with only small lumps remaining.

Step 3: Whisk the Custard
Crack the egg directly on top of the mashed banana. Add the milk, ground cinnamon, vanilla extract, and the optional pinch of salt. Use the same fork to whisk everything together vigorously until the egg is fully incorporated and the mixture is a cohesive, slightly thick custard.

Step 4: Soak the Bread
Take one slice of bread and place it flat into the banana custard. Let it soak for about 15-20 seconds per side. You want the bread to absorb the custard, but not become so saturated that it falls apart. The banana will create a thick layer that coats the outside. Repeat with the second slice of bread.

Step 5: Cook to Golden Perfection
Carefully lift the soaked bread slices from the dish, allowing any excess to drip off, and place them onto the hot, buttered pan. You should hear a gentle sizzle. Cook for 2-4 minutes per side, until the exterior is a deep golden-brown and beautifully caramelized from the banana sugars. The inside should be soft and custardy.

Step 6: Serve Immediately
Transfer the hot French toast to a plate and serve immediately with your favorite toppings.