Preheat oven to 375°F (190°C) and line a baking sheet with parchment paper.
Whisk flours, sugar, baking powder, baking soda, cinnamon, nutmeg, and salt in a bowl.
In another bowl, whisk eggs, Greek yogurt, milk, vanilla, and melted butter.
Stir wet ingredients into dry ingredients just until combined.
Fold in diced apples gently.
Scoop spoonfuls of batter onto prepared baking sheet and shape slightly.
Bake 16–20 minutes until golden and cooked through.
Whisk glaze ingredients and drizzle over slightly cooled fritters if desired.