Preheat your oven to 400°F (200°C). Grease 20 muffin cups to prevent sticking later on. Getting this step out of the way first ensures a smooth flow once your batter is ready.

Cut a 1/2-inch hole into the larger part of the butternut squash and cover it with a damp paper towel. Microwave the squash in 3-minute increments, turning it slightly after each round, until easily pierced with a fork (about 9 to 12 minutes total). Let the squash cool until it can be handled comfortably, about 20 minutes. I like to do this step ahead of time when possible, so the squash is fully cooled and ready to use.

Halve the cooled squash lengthwise and remove the seeds. Measure out 1 1/2 cups of the cooked squash flesh into a large mixing bowl. Add the eggs, water, neutral cooking oil, granulated sugar, and packed brown sugar. Mash and whisk everything together until the mixture is well combined and somewhat smooth.

In the same bowl, add the whole wheat flour, plain flour, baking powder, baking soda, ground cinnamon, salt, ground nutmeg, ground cloves, and pumpkin pie spice. Whisk everything together until a smooth and even batter forms, with no streaks of flour remaining. Then fold in the raisins and chopped walnuts gently, distributing them evenly throughout the batter. For an extra pop of flavor, I sometimes sprinkle a little extra cinnamon right before folding in the nuts and raisins.

Spoon the batter into the prepared muffin cups, filling each about halfway to two-thirds full. Transfer to the oven and bake until a toothpick inserted into the center of a muffin comes out clean, about 15 minutes. Once baked, let the muffins cool in the pans for 10 minutes, then remove them and finish cooling on a wire rack. I like to enjoy one warm, but they’re just as good at room temperature.