Combine spinach, drained artichoke hearts, shredded Gruyère, and cream cheese or sour cream in a food processor, and pulse until smooth, stopping to scrape down sides as needed. This should be about 15 -20 pulses max. Then pour the mixture out into a bowl and season lightly with salt, pepper, and garlic powder to taste.

Preheat oven to 375°F. Line 2 baking sheets with parchment paper (no need to butter or spray). Separate crescent roll dough triangles where perforated. (Optional: Cut each triangle in half from tip to base, creating 2 triangles out of each) - I left my triangles the size they were. Gently pat and stretch the wide end of each triangle to make it a bit wider. Spoon about 1⁄2 tablespoon of filling on wide end of each triangle. Roll from widest part of triangle, pinching sides slightly, toward tip, enclosing filling; curve slightly to create a crescent shape. Place on prepared baking sheets, about 1 inch apart.

Lightly brush beaten egg over surface of each crescent. Bake in preheated oven until golden brown, about 12 minutes.