Preheat the oven to 400°F. Line a baking sheet with parchment paper. Combine sugar and cinnamon in a small bowl; set aside.
Unfold pastry sheet on a clean surface. Brush sheet with a little water to moisten and sprinkle with half of sugar mixture. Press mixture gently into dough using a rolling pin and turn over. Moisten pastry and sprinkle with remaining sugar mixture.
Gently roll the dough to a 12 x 12-inch square. Press pecans into dough and fold a 2-in strip in towards the center of the dough from the right and left sides. Fold each side in again. You should have 3 layers of dough on each side of the center. Fold this over to form a ‘U’. Cut the dough into 12 ½-inch pieces and place on a cookie sheet. The cookies should be about 1 ½ inches apart. Pinch the bottoms of each cookie to form the point of the heart. Bake for 13 to 15 minutes or until the pastry is fully cooked. Let cool on the cookie sheet.