French Toast for Challah or Sandwich Bread

From America's Test Kitchen Season 2: French Toast, Waffles, and Breakfast Strata

French toast started out as a simple way to use up old bread by dipping it in a beaten egg and frying it. We wanted French toast that was crisp and buttery on the outside, soften and custardlike inside. Furthermore, we wanted it to be sweet enough to eat with just a sprinkling of powdered sugar, but not so sweet that we couldn’t top it with syrup or macerated fruit if we chose.

Different breads make for very different French toasts. In our tests of half a dozen types of breads, we got the best results from challah, which added the most flavor and richness. (Pre-sliced sandwich bread will all work in a pinch, but other breads should be avoided.) Because we didn’t want our toast to be too eggy, we dropped one egg from the recipe and increased the milk. A little salt, sugar, and vanilla filled out the flavor of our basic recipe, with almond extract and cinnamon as nice alternatives.

Next we set about achieving the almost deep-fried crispiness we wanted. Using more sugar, increasing the butter in the skillet, and using a higher heat didn’t work. Ultimately, the answer was flour. A batter with flour and melted butter got the outside of the challah evenly crisped and brown, while just enough moisture permeated through to the interior to keep it custardlike, but not heavy.