1. Preheat the oven to 200 °C. Peel sweet potatoes and grate coarsely.
2. Put butter and sugar in a bowl and beat until foamy. Add sweet potatoes, egg, honey and lemon zest.
3. Mix all dry ingredients in a second bowl. Then fold into the sweet potato mix.
4. Line a baking sheet with baking paper. Using two tablespoons, place small piles of dough on the baking paper and press down a little.
5. Bake the scones in the middle of the oven for 10-15 minutes until golden brown. Allow to cool and then place on a grid.