In a medium bowl, toss the finely diced apples with 2 tbsp sugar, 1 1/2 tsp cinnamon, and lemon juice. Let rest for 5 minutes so the apples soften slightly and release their aromatic juices.

Pour 2 to 3 inches of oil into a heavy cast-iron Dutch oven or deep skillet. Attach a candy/deep-fry thermometer and heat oil over medium heat to 365°F (185°C). Maintaining oil temperature between 360°F and 370°F is critical for a crisp, non-greasy crust.

In a large mixing bowl, whisk together flour, 1/4 cup sugar, baking powder, salt, and nutmeg. In a separate bowl or measuring cup, whisk eggs, milk, melted butter, and vanilla.

Pour wet ingredients into dry ingredients and stir with a wooden spoon just until combined. Gently fold in the spiced apples along with any syrupy juices from the bowl. The batter will be thick, chunky, and packed with apples.

Using a 1/3-cup measuring cup or large cookie scoop, drop portions of batter into the hot 365°F oil, flattening slightly with the back of a spoon to create an irregular, craggy oval shape. Fry 2 to 3 fritters at a time so you don't drop the oil temperature.

Fry for 2 to 2 1/2 minutes on the first side until deep mahogany-golden and puffed, then flip with a slotted spider strainer and fry for another 2 minutes until cooked through and crunchy. Transfer to a wire cooling rack set over a paper towel-lined baking sheet.

While fritters are still warm, whisk together powdered sugar, milk, vanilla, and a pinch of salt in a shallow bowl until smooth and runny.

Dip each warm fritter directly into the glaze, spooning extra glaze over top to coat every craggy crevice. Place back on the wire rack. Within 2 to 3 minutes, the warm glaze will set into a delicate, crackly, sheer sugar shell. Serve warm!