1Bring a large pot of lightly salted water to a boil. Cook peas in the boiling water, stirring occasionally until tender, about 5 minutes. Drain and transfer to a bowl; mash peas using a fork.
2Mix flour, Parmesan cheese, egg, milk, baking powder, salt, and pepper into mashed peas, adding more milk or flour until mixture holds together. Shape pea mixture into patties about 1/2-inch thick.
3Heat olive oil in a skillet over medium heat; fry patties until golden, 3 to 4 minutes per side.