In a bowl, sift together the flour, baking powder and baking soda, then add a pinch of salt and the nutritional yeast.

In a separate bowl, pour the soy milk, add the vinegar and mix; the milk should curdle instantly.

Using a whisk, gently mix the dry powders, then add the curdled milk and the melted margarine.

Mix everything very briefly with a spatula using circular movements, as if folding in whipped egg whites you don't want to deflate.

Cut the ham slices and the melting cheese slices into rounds the size of a pancake using a cutter or a glass and a knife, making about 2 rounds per ham slice, keeping the offcuts for other pancakes.

Cook the pancakes on a lightly oiled pan or griddle over medium-high heat for 30 seconds on the first side, then add one cheese round, one ham round and another cheese round.

Cover with a small amount of pancake batter, cook for another 30 seconds, then flip and cook for 1 more minute.