Hazelnut Filling

Combine nut flour, sugar, corn syrup, cinnamon, and half of the water in a bowl. Blend together by hand with a spatula or mixing spoon, slowly adding the remaining water until a smooth consistency is achieved that will not tear the dough when spread on. More water can be added if necessary, and the consistency can still be adjusted with water on the following day. Store for up to 5 days in the