In a wide skillet, sauté the apples in the butter for about six minutes.

Add sugar and cinnamon, and sauté another two minutes. Allow to cool slightly.

Melt white chocolate and add three-fourths cup heavy cream to form a smooth ganache. Add vanilla extract and let cool to room temperature.

Beat the remaining three-fourths cup cream and gently fold into the ganache.

Using the dough hook on your mixer, beat the softened butter with the sugar and salt for about four minutes. Add eggs, hazelnuts, and flour, and knead just until a dough forms.

Refrigerate dough for one and a half hours.

Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius). Line a baking sheet with parchment paper.

On a floured surface, roll out dough 1/3 inch (one centimeter) thick. With a very sharp knife, cut the dough into squares measuring 1/3 inch by 1/3 inch (one centimeter by one centimeter). Place cubes on prepared baking sheet and bake for about 12 minutes, or until nicely browned.

Place two to three teaspoons (depending on the size of the cups) of the sautéed apples in the bottom of each cup. Pipe three to four tablespoons of the vanilla cream onto the apples and top with pastry cubes.