1. Heat the oven to 400°F. Stir the cream cheese, 1/4 cup Parmesan cheese, black pepper and garlic powder in a medium bowl until the mixture is smooth.
2. Reserve 1/2 cup red peppers. Place the mayonnaise and the remaining red peppers into a food processor. Cover and process until the mixture is smooth. Spoon into a serving bowl. Cover and refrigerate until ready to serve.
3. Unfold the pastry sheet on a lightly floured surface. Roll the pastry sheet into a 12 x 9-inch rectangle. With the short side facing you, cut the rectangle in half lengthwise.
4. Spread about 1/2 cup cream cheese mixture on each rectangle to within 2 inches of the edge. Divide the asparagus and reserved roasted peppers between the pastry rectangles. Fold the long sides of the pastry over the filling and press to seal. Place the rolls, seam-side down, onto a baking sheet. Tuck the ends under to seal. Brush the rolls with the egg and sprinkle with the sesame seeds.
5. Bake for 15 minutes or until the rolls are golden brown. Cool the rolls on the baking sheet on a wire rack for 10 minutes. Cut each roll into 6 slices. Serve warm with the red pepper sauce for dipping.