Preheat oven to 350 F. Lightly grease a 9×13 inch casserole dish with olive oil.
Spread 3 tablespoons of ricotta mixture evenly over each lasagna noodle, leaving a little room around the side edges and 1/2 inch at each end.
Scatter about 3 tablespoons of spinach mixture over the ricotta. Starting at the bottom end, roll noodle up and place, seam side down, in the casserole dish. Continue with all remaining noodles. Pour the white sauce over the rolls in thick ribbons.
Bake for 20 to 25 minutes, until edges are lightly browned and white sauce is thickened. If after 25 minutes the rolls are not browning but the edges are crispy, place under a broiler on low heat for a minute or two, keeping a very close eye so that they don’t burn.
Remove from oven and smother on remaining pesto. Garnish with additional pumpkin seeds and serve!