Start by preparing your garlic aioli so that the flavors have time to meld while you are preparing your fritters. In a food processor add the lemon juice, lemon zest, dill and garlic and pulse until minced thoroughly. Then add the mayonnaise and sour cream and pulse a few times to combine. Then set aside or in the fridge until needed.
In a large bowl whisk together the ricotta cheese and egg until thoroughly combined. Add to the mixture the zucchini, corn, garlic, lemon zest and stir with a spatula. In a medium bowl whisk together the flour, cornmeal, baking soda and salt and pepper and then add that mixture to the zucchini mixture and stir until combined.
Heat 1/8 inch of vegetable oil in a large nonstick skillet over medium heat. Working in batches, form small patties out of the zucchini mixture and carefully place them into the oil. Cook the fritters until they are golden brown. Drain on paper towels and then sprinkle with salt. Serve warm with the garlic aioli.