Preheat your oven to 400ºF or your air fryer to 375ºF. In a medium bowl, whisk together the yogurt, egg, maple syrup, and cinnamon until smooth.
Use your fingers or the back of a spoon to make a well in the center of each bread slice without tearing it. Pour the custard mixture into the wells, dividing it evenly between the slices. Top the custard with your favorite berries.
If you’re using an oven: Place the prepared bread slices on a baking sheet and bake them for 10 to 13 minutes, or until the custard is set and the bread turns golden brown.
If you’re using an air fryer: Carefully place the prepared bread slices in the basket of your air fryer and cook them for 7 to 10 minutes, until the custard sets and the bread browns nicely.
Once done, transfer the toast to a plate and drizzle with extra toppings of your choice. You can also sprinkle some powdered sugar for an extra touch of sweetness.