Heat oven to 375ºF. Unroll crescent dough on lightly floured surface; pat into 12x8-inch rectangle. Firmly press perforations together to seal. Cover with spinach mixture. Roll up dough, starting at one long side; cut crosswise into 12 pieces. Place, cut-sides down, on baking sheet. Brush lightly with egg; sprinkle with sesame seed and crushed pepper.