Combine the flour, sugar, salt and baking powder, and whisk until combined.
In a small bowl whisk the milk and egg until combined, add in the vanilla and lemon juice and whisk until combined. Add mixture to dry ingredients and mix until just incorporated.
Stir in the blueberries and mash them just a bit, just enough to pop them a bit. They have a tendency to "pop" pot of the edges of the batter when frying if left whole. They don't pop out of the pot, they just float. If you see that, simply scoop out and discard.
Heat oil to 370 degrees.
Fry heaping spoonfuls of the batter (make sure blueberries are in every scoop) until cooked through (about 2-3 minutes). I typically use a small cookie scooper for this. Fritters will pass golden brown and begin to brown.
Make sure to carefully spin fritters around using a fork or tongs as they fry so they cook and brown evenly.
If frying in a sealed fryer, shake basked around just a bit during frying to ensure even rotation of cooking. If cooking in an open frying pan/pot.
Once fritters are removed from the fryer, place them on a cooling rack with paper towels under to catch any drips.
Sift or shake powdered sugar on fritters or dip or drizzle them with a simple lemon glaze (below).
To make glaze simply combine 1½ cups powdered sugar, 1 TBS of fresh lemon juice and 1TBS water (more as needed). Stir until smooth and drizzle over fritters or go ahead and dunk them in. If dunking them in, allow them to set for a few minutes and enjoy...they don't really "keep" that way. You don't want the glaze to thin or runny, you want it on the thicker side. You can decide to coat them twice after the first coat dries.
Fritters are best enjoyed soon after you make them while still warm. For best results fry fritters in small batches of 3 or 4.