In a large bowl, combine flour, ground almonds, 1 tsp. sugar, salt, pinch cinnamon and baking powder. Set aside.
Combine egg, milk and vanilla. Gently stir the wet ingredients into the dry. Let the batter rest in fridge for 30 minutes.
Peel and core apples. Slice apples into 1/2-inch thick rings. Sprinkle apple slices with lemon juice to stop them from browning.
Meanwhile, in deep fryer or deep saucepan, heat about 2 to 3-inches oil, over medium heat to 375 degrees F.
Dredge apple rings in flour, shaking off excess. Then dip into batter to evenly coat. Carefully add fritters to hot oil, in batches, turning once. Fry fritters until apple is tender and batter is golden brown, about 3 minutes. Transfer to paper towels to remove excess oil.
Dip fritters in icing sugar. Alternatively, make cinnamon sugar by combining 1 cup sugar with 1 tbsp. ground cinnamon and dip fritters in the cinnamon sugar. Serve warm.