This is baking powder with added vanilla flavouring (actually “vanillin”.) It’s used in Italy for baked sweet goods, and negates the need to add vanilla separately to a recipe.
It comes in a small 1/2 oz (16g) sachet, which Italians call a “bustina.” Recipes will usually call for it by the sachet, half-sachet or by the teaspoonful (“cucchiaio” in Italian.)
Many Italian cooking purists prefer to use regular baking powder, and add the vanilla flavouring to what they are making via real vanilla beans.
Each packet holds enough to raise and flavour 500g of flour.
If the recipe calls for vanilla separately, you are fine just using regular baking powder. If it doesn’t, you’ll probably want to add a small amount of vanilla sugar or vanilla extract to the recipe along with regular baking powder.
1 sachet weighs 16g and holds 1 teaspoon of Vanilla Baking Powder.