Preheat oven to 350 degrees Fahrenheit. Line two sheet pans with silicone mats.

In a large bowl, whisk all ingredients to combine. Mix until creamy and no lumps of starch remain.

Divide the batter between the two prepared pans. Use an offset spatula to spread the batter evenly onto the mat.

Stir together sugar and cinnamon. Sprinkle over the kichel batter.

Bake for seven to eight minutes; remove from oven and use a pizza cutter to cut the kichel. Make two evenly-spaced long cuts down the length of the pan. Then make seven equally-spaced cuts across the width, resulting in 24 four-by-two-inch rectangular crackers. Bake another 15 to 20 minutes. Remove from oven and cool.

Peel and shred the apples. In a large saucepan, mix apples, sugar, lemon juice, and cinnamon. Cook over low heat for 20 minutes and sift in the potato starch. Stir and cook another 10 minutes or until the mixture thickens like jam. Let cool.

Place a kichel on a plate. Top with two tablespoons cooked apple filling and another kichel.