Melt butter in a small skillet over medium heat. Add shallots and cook, stirring, until softened, about 3 minutes. Transfer to a large bowl. Add eggs, flour, baking powder, salt and black pepper to taste. Stir until completely combined. Mix in the sweet potatoes.
Heat ¼-inch vegetable oil in a large skillet over medium-high heat. A piece of batter will sizzle immediately when the oil is hot enough. Scoop ¼ cup of mixture onto a greased spatula and use your hand to smash it into a patty. Gently slide the fritter off the spatula and into the oil. Repeat to make enough fritters to fill, but not crowd, the pan.
Cook 4-5 minutes per side, or until golden brown and crispy, adjusting heat as needed. Transfer to paper towels to drain and season with salt. Repeat shaping and frying the fritters until all of the mixture has been used. Serve with spicy honey butter sauce.
Combine butter, honey and hot sauce in a microwave-safe bowl. Heat for 15 second intervals, whisking in between, until mixture is smooth and combined. Serve with fritters.