Sift flour and salt together in a large bowl.
Add sugar to flour. Mix.
Lightly beat egg in another bowl.
Add butter, milk, lemon zest and vanilla to beaten egg
Add liquids to dry ingredients all at once.
Whisk, stir or beat until smooth.
Stand for at least 30 min in the fridge or preferably overnight.
Sift baking powder over batter. Mix in thoroughly.
(If you're not going to let the mixture stand then shift the baking powder in with the flour.)
Add optional fruit
Cook hotcakes on a large griddle or frying pan. Heat until dropped water bounces, sputters, and disappears.
I normally use 1/4 Cup of mixture per Hotcake. Use 1/2 Cup for larger ones and 1 tablespoon for tiny ones. Pour the batter from just above the pan.
Cook for 2-3 min on the first side. Turn over when bubbles appear but before they break (or when they just start to burst).
Cook the second side for 1 min - it won't brown as well as the first side.
Keep hotcakes warm by placing inside a folded tea towel or paper towel.
Repeat with remaining batter, lightly greasing between batches if necessary.