Preheat and prepare: Preheat your oven to 350°F (175°C) and line a muffin tin with paper liners.
Mix dry ingredients: In a medium bowl, sift together the flour, cocoa powder, and baking powder. Add the sugar and stir to combine. This ensures that all the dry ingredients are well mixed and free from lumps, which is important for a smooth batter.
Combine wet ingredients: In a separate bowl, whisk together the warm water, vegetable oil, and eggs until the mixture is smooth and fully combined.
Combine wet and dry mixtures: Gradually add the wet ingredients to the dry ingredients, gently stirring until just combined.
Add raisins and orange peels: Fold in the raisins and chopped candied orange peels. If you like, you can also add a pinch of cinnamon or nutmeg for an extra holiday touch.
Fill muffin liners: Spoon the batter into the prepared muffin liners, filling each about 2/3 full to allow room for the muffins to rise.
Bake: Place the muffin tin in the preheated oven and bake for 18–20 minutes, or until a toothpick inserted into the center of a muffin comes out clean.
Cool and Serve: Allow the muffins to cool in the tin for 5 minutes, then transfer them to a wire rack to cool completely. Serve as they are, or decorate with powdered sugar or a drizzle of melted white chocolate for a festive look.