Preheat oven to 450 degrees F (230 degrees C). Line a baking sheet with parchment paper.
On a lightly floured surface, roll puff pastry to 13x13 inches square. With a sharp knife, trim to 12x12 inches. Cut into 3 equal strips, 4x12 inches. Poke each strip several times with a fork. Arrange on prepared baking sheet. Sprinkle with hazelnuts.
Bake in preheated oven for 8 to 10 minutes, or until puffed and golden. Allow to cool. If not equal in size, trim with a serrated knife, using a gentle sawing motion.
Melt chocolate in a bowl over barely simmering water, stirring constantly, until smooth. Cool to room temperature. In a large bowl, beat together cream cheese, brown sugar and coffee until smooth. Blend in melted chocolate. Fold in ground hazelnuts and almonds. In a large bowl, whip cream until peaks form. Fold 1/3 of the whipped cream into the cheese mixture, then quickly fold in remaining whipped cream until no streaks remain.
Spread 1/3 of filling on a strip of puff pastry. Repeat layers. Refrigerate for 3 hours, or until set. With a serrated knife, cut into 10 slices using a gentle sawing motion.