In a large mixing bowl, combine the grated sweet potatoes, diced onion, minced garlic, flour, beaten eggs, ground cumin, paprika, salt, pepper, and chopped parsley (if using). Mix until well combined.
Heat vegetable oil in a skillet over medium-low heat, enough to generously coat the bottom. Take about ¼ cup of the mixture and form into a ball and flatten into the fritter shape. Repeat with the remaining mixture.
Carefully place the formed fritters into the hot oil, working in batches to avoid overcrowding the skillet. Fry each fritter for about 3-4 minutes on each side, or until golden brown and crispy. Transfer the cooked fritters to a paper towel-lined plate to drain excess oil.
In a small bowl, whisk together the Greek yogurt, lemon zest, lemon juice, honey, and a pinch of salt until smooth and well combined. Adjust the sweetness and tartness to your taste by adding more honey or lemon juice, if desired.
Serve the sweet potato fritters hot, accompanied by the honey-lemon yogurt sauce for dipping or drizzle over the top.