Preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper.
In a mixing bowl, combine the softened cream cheese, lump crab meat, green onions, garlic powder, and Old Bay seasoning. Mix until well combined.
Unroll the crescent roll dough and separate it into triangles.
Place a generous tablespoon of the crab mixture at the wide end of each triangle.
Roll the crescent dough around the filling, starting from the wide end and rolling towards the point. Pinch the edges to seal.
Place the rolled crescents on the prepared baking sheet. Brush the tops with the beaten egg and sprinkle with sesame seeds if desired.
Bake in the preheated oven for 12-15 minutes or until golden brown.
Remove from the oven and let cool slightly before serving.