In a bowl, toss the cubed butternut squash with olive oil, salt, and black pepper until evenly coated.
Sprinkle the sliced sage on the bottom of a 7-inch round cake pan insert, metal cake pan, or foil pan, and place the squash on top.
Place the pan in the air fryer and cook at 400°F for 10 minutes.
Stir to incorporate the sage, then continue cooking until the squash is tender and lightly caramelized at the edges, about 3 minutes more.
Pour the beaten eggs over the cooked squash, then dollop the ricotta cheese evenly over the eggs.
Sprinkle with cayenne pepper.
Reduce the air fryer temperature to 300°F (150°C) and cook until the eggs are set and the frittata is golden brown on top, about 20 minutes.
Remove the pan from the air fryer and cut the frittata into wedges to serve.
Notes & Wine Advice
Wine Advice:
Pair this autumn-inspired frittata with a medium-bodied white wine such as Chardonnay or a light red wine like Pinot Noir to complement the earthiness of the squash and richness of the ricotta.