© Denzil Green
Almond Extract is a concentrated liquid that provides almond flavour to foods.
Most almond extracts are made from almond oil blended with the flavourless alcohol, ethyl. Bitter-almond oil is generally used rather than oil from sweet almonds as it has more of an almond flavour.
Artificial almond extract is made from benzaldehyde (which is the element in almonds and apricot kernels that tastes like almond), ethyl alcohol, and water.
The American Food and Drug Administration distinguishes between “pure” and “natural” almond extract. Pure must be made from bitter almonds, or kernels from peaches, plums, or cherries. “Natural” can be made from caccia bark. 
Use sparingly, as a little goes a long way.
1 tablespoon of Amaretto liqueur per teaspoon of almond extract called for.
A non-nut extract such as vanilla or banana, if you don’t care about replicating the flavour or are cooking for someone with nut allergies.
Don’t use real almond extract in anything you are making for anyone with nut allergies. Imitation may be okay; check with the manufacturer.
 Steingarten, Jeffrey. The man who ate everything. Toronto, Canada: Random House. 1997. Page 74.