Whisk flour, sugar, baking powder, baking soda and salt together in a medium bowl. Make a hole in the middle and set aside.
Whisk 3/4 cup buttermilk, egg and vanilla in a small bowl until well-mixed. Pour into the middle of the dry ingredients. Using a wooden spoon or a spatula, fold the mixture until just combined. It will be lumpy with tiny streaks of flour. If the batter is too thick, stir in the remaining 1/4 cup of buttermilk. Use immediately.
Heat a non-stick frying pan over medium-low heat. Place a damp cloth on the table counter. When water sizzles when sprinkled into the pan, remove the frying pan and place on top of the damp cloth for 3 seconds and place it back on the stove - doing this will ensure the heat in the frying pan is even.
Pour in 1/8-cup to 1/4-cup of the pancake mix into the frying pan. Cook until bubbles start to emerge on the surface of the batter, then slide a spatula below the pancake. Check that the bottom is golden brown (if not, let the pancake cook a while more) then flip it to cook a few minutes on the other side, until golden brown in colour.
Repeat steps 3 and 4 until all the batter is used up.
While the rest of the pancakes are cooking, place the cooked pancakes on a baking sheet (overlapping each other slightly), cover with aluminum foil and keep warm in an 80 degrees Celsius oven for up to 30 minutes - the pancakes will gradually dry out, so serve as soon as possible.
Serve the pancakes with plenty of good-quality butter and maple syrup/honey.
NOTES
- To substitute the buttermilk: combine 3/4 cup (180ml) of milk with 1 tablespoon white vinegar. Let stand for 15 minutes and stir before using.- Edit 26 Sep 2017: I've reduced the amount of buttermilk to 3/4 cup as I sometimes find the batter too liquidy, which prevents me from getting a thick pancake.