Buttermilk French Toast is made by dipping slices of stale bread in egg buttermilk custard and pan-fried until they are crispy golden brown from the outside and fluffy from the inside.
In a mixing bowl, mix together eggs, buttermilk, sugar, and salt, dunk the bread slices into the mixture.
Heat the butter in a large nonstick pan over medium-high heat.
Transfer the bread slices to the pan (cook the bread in batches) and cook for 1-2 minutes, then flip on the other side and cook for another 1-2 minutes until golden brown.
Notes
I also recommend using a day-old bread because it absorbs the custard better.