Measure out your dry ingredients (almond flour and powdered sugar).
Add dry ingredients to a food processor or a medium sized mixing bowl.
Pulse a few times in the food processor or mix together in the bowl, just until roughly combined.
Add in 1 tbsp egg white or water, and almond extract to the food processor or bowl.
Pulse or run the food processor until all ingredients combine and begin to form a ball - you may have to add a little more egg white or water (up to 1 tbsp more) to get it to bind together. Add gradually so it doesn't get too wet! You can always add more almond flour and powdered sugar in equal parts if it does get too wet.
If doing this by hand, you can knead it together in the bowl until it begins to form one large mass. Again, if it gets too sticky and wet, add more powdered sugar and almond flour in equal parts until the texture resembles play doh!
You should be left with a malleable, dough-like ball that you can use for a variety of other recipes. We store our marzipan in the fridge for up to a week; you can also wrap it and freeze it for longer term storage, just place back in the fridge a day or two before you plan to use it!