If your bread is fresh, slice it 1-inch thick and toast in a 300°F oven for 5-7 minutes per side. Let cool completely. This dries it out to absorb the custard without falling apart.
In a shallow dish, whisk together the chickpea flour, ground flaxseed, cinnamon, and nutmeg. Slowly pour in the oat milk, maple syrup, and vanilla, whisking until completely smooth and no lumps remain.
Dip each bread slice into the custard for 15-20 seconds per side. Let the excess drip off. The bread should be fully saturated but still firm enough to hold its shape when lifted.
Heat a skillet over medium heat. Add 1 tablespoon of vegan butter. Once melted and bubbling, place the soaked bread in the pan (work in batches if needed). Cook for 3-4 minutes per side, until deep golden brown with lacy, caramelized edges.
Transfer the cooked slices to a wire rack. Rest for 2 minutes. This lets steam escape, keeping the outside crisp and the inside tender. Do not skip this step.
Serve immediately with a drizzle of maple syrup, a pat of vegan butter, fresh berries, and a dusting of cinnamon.