Whey protein powder, unflavoured
(or vanilla, can be replaced with 1 cup flour)
Preheat the oven to 400°F. Grease each cup of a standard 12-cup muffin tin, and set aside. In a large bowl, combine flour, baking powder, salt, cinnamon, ginger, nutmeg, and cloves. Set aside. In a separate bowl, mix together the yogurt, egg, honey, coconut oil, and sweet potato puree. Beat until smooth. Make a well in the center of the dry ingredients, and pour in the wet mixture. Stir them together, being careful not to over-stir. Gently fold in the chopped apples. In a small bowl, stir together the packed brown sugar, pecan pieces, and melted butter to make the streusel. Fill the prepared muffin tin cups 2/3 full. Sprinkle each muffin with a heaping teaspoon of streusel topping. Bake for 15 to 20 minutes, or until muffins are golden and spring back when touched. Cool on a wire rack for several minutes, and serve warm.