Preheat oven to 375°F and line two baking sheets with parchment paper, or aluminum foil and spray with olive oil spray; set aside.
In a large microwave-safe bowl, melt butter. To the melted butter, add the egg and beat with a fork to combine. Add the chipotle seasoning, salt and pepper, and stir to combine well. Add the flour and stir to combine. Add the sweet potato and zucchini; toss to combine. Mixture will be loose and a bit soggy. Using a ½ cup measure, form fritters by transferring one heaping ½ cup of vegetable mixture from mixing bowl directly to baking sheets. Mound the mixture into loosely packed circular shapes.
Bake fritters for about 10 minutes. If fritters have released any liquids, either from the zucchini releasing water, or the butter-egg mixture, just push the liquid back into a fritter using a spatula.
Lower oven temperature to 350°F and bake for about 15 minutes. Carefully flip fritters over and bake for about 15 more minutes, or until browned. Fritters will be browned but soft upon removal from oven. Allow them to cool and firm up on the baking sheets for at least 10 minutes before moving or serving them.