Line the basket of your air fryer with a piece of parchment paper or air fryer basket liners. Brush lightly with oil or spray lightly with an oil sprayer.
Whisk together flour, sugar, baking powder, salt, and cinnamon in a medium bowl.
Make a well in the center of the flour mixture and add milk, vanilla, lemon juice and eggs. Stir until evenly combined. Fold in the apples.
Drop about ¼ cup of the batter onto your lined air fryer basket. Depending on the size of your air fryer you may only be able to fit 2 fritters at a time.
Lightly dab the tops of the fritters with oil using a pastry brush or oil sprayer. Set the air fryer to 400 degrees for 4-5 minutes or until deep golden brown. Flip fritters over and repeat until both sides are golden brown.
Place apple fritters on cooling rack and drizzle with butter glaze while still warm.
Place butter in a small saucepan over medium-high heat. Continuing melting the butter until it starts to foam and turn brown.
Once browned, remove from heat to cool slightly. You should smell a nutty aroma and see brown specks in the butter.
Add powdered sugar to a small bowl. Add browned butter and milk whisking until smooth. (If mixture is too thin for your liking, simply add more powdered sugar.) Set aside.