Start off by whisking the eggs, milk, sugar, and vanilla, salt, and cinnamon in a large bowl. You can use a whisk or hand mixer here.
Now dip the sliced bread (1-inch thick) into the french toast custard. You don’t want to soak it unless your bread is very stale.
Heat the butter in a frying pan until melted and place your dipped toast into the pan. Brown both sides until golden in color. Serve warm.