Combine apples and ½ teaspoon cinnamon in a bowl and toss until apples are coated with cinnamon. Set aside.

In a separate, large bowl, combine flour, sugars, baking powder, remaining ½ teaspoon of cinnamon, and salt, and whisk until well-combined.

Crack eggs in a separate bowl and beat until pale yellow and frothy. Add milk and vanilla extract, whisking together.

Slowly pour melted butter into the wet ingredients while whisking until well-combined.

Pour wet ingredients into dry and fold together until about halfway combined. Add cinnamon-coated apple pieces and continue folding until just combined.

Fill a Dutch oven or large saucepan 2-3 inches deep with oil for frying. Fix a candy thermometer to the edge of the pan and set heat to medium-low. Heat oil to 360-365°F (175-185°C).

While oil is heating, prepare glaze by whisking together powdered sugar, apple cider, and vanilla extract until smooth. Set aside.

Once oil has reached temperature, use a large spoon or ice cream scoop to scoop about 3 Tablespoons of batter and drop into the oil. Repeat with 2 more scoops and fry each for 60-75 seconds on each side, or until golden brown.

Use tongs to remove apple fritters to a paper towel-lined plate and allow to cool several minutes before dipping in glaze. Transfer to a cooling rack to allow glaze to set.

Apple fritters are best enjoyed warm the same day they are made.