Whisk the oat milk, chickpea flour, cornstarch, maple syrup, vanilla, cinnamon, salt, and kala namak if using in a wide, shallow dish until completely smooth. Let the batter sit for 5 minutes so the chickpea flour hydrates, then whisk it again. It should look like thin pancake batter.

Heat a large nonstick or cast-iron skillet over medium-low heat and add 1 tablespoon of the vegan butter, swirling to coat the pan. Medium-low is the sweet spot here, because a pan that runs too hot browns the outside before the custard in the center has set.

Dip one slice of bread into the batter and let it soak for 15 to 20 seconds per side if the loaf is sturdy and day-old. For softer sandwich bread, dip for just 3 to 5 seconds per side. Lift the slice and let the excess batter drip back into the dish.

Place the slice in the skillet and cook for 2 to 3 minutes per side, until it is deep golden brown and crisp at the edges. Cook only two or three slices at a time so the pan stays hot and the bread does not steam.

Add another small piece of vegan butter between batches, and lower the heat if the slices are browning faster than the center is setting.

For thick slices that still feel soft in the middle, move them to a rack set on a baking sheet and finish in a 350F (175C) oven for 5 to 8 minutes, which sets the custard without drying the crust. Serve warm with maple syrup and berries.