Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper or lightly grease it.
Chop the fresh spinach into small pieces. If using frozen spinach, thaw, drain, and squeeze out excess moisture.
In a medium mixing bowl, combine the cream cheese, shredded mozzarella cheese, grated Parmesan cheese, garlic powder, and chopped spinach. Mix until smooth and evenly combined.
Unroll the crescent roll dough onto a clean surface. Separate the dough into 8 triangles.
Place about 1–2 tablespoons of the spinach and cheese mixture at the wide end of each triangle. Roll up each triangle from the wide end to the pointed tip, sealing the edges slightly.
Place the assembled rolls on the prepared baking sheet, spacing them evenly apart.
Bake in the preheated oven for 10–12 minutes, or until the crescent rolls are golden brown and flaky.
Remove from the oven and let cool for 2–3 minutes. Serve warm, garnished with additional Parmesan cheese or fresh herbs if desired.
Notes
To make ahead, freeze unbaked rolls on a baking sheet, then transfer to a freezer-safe bag. Bake directly from frozen, adding 2–3 minutes to the cooking time.