Preheat oven to 350°F and spray a mini donut pan with nonstick spray (one with flour works great).

In a large bowl, whisk together flour, sugar, baking powder, and salt.

In another bowl, whisk together egg, vanilla, maple syrup, and milk, until egg is beaten and ingredients are combined.

Pour the wet ingredients into the dry and stir until just incorporated.

Stir apple into the batter. Do not overmix.

Fill donut wells about 1/2 full, using a spoon to spread dough evenly around the circle. Bake for 10 minutes.

After baking, let rest in pan 1 minute, then turn out into a cooling rack.

Repeat with remaining batter.

Eat while warm, or let cool completely and store for later.