In a medium bowl, mix together ricotta, Parmesan, lemon zest, basil, and oregano; set aside.

Heat a large skillet over medium heat. Once pan is hot, add oil and garlic. Saute garlic, stirring constantly, for 1 minute. Add spinach. Cook until spinach wilts, 2 to 4 minutes. Remove to a bowl.

Butter one side of each of the 4 pieces of bread. Sprinkle the butter side of the bread with garlic powder, to your liking.

Place bread, buttered side down, in the same skillet that you used for the spinach. spread half the ricotta mixture over the bread. Layer 1/2 the spinach on top of the ricotta. Top sandwich with a second piece of bread, buttered side up.

Cook until bread is golden brown, 2 to 3 minutes. Flip sandwich over, and cook for another 2 to 3 minutes, until bread is golden and cheese has melted.

Cut in half and serve warm...or cold. I ate the second sandwich right of the fridge and it was still totally delicious!