For the dressing, combine the apple spice yogurt, vinegar, mustard, salt and pepper in a small bowl and whisk well to combine. Add more salt if necessary. Set aside.
For the slaw, cut the tough ends off of the Brussels sprouts and remove the outer leaves. Rinse well.
Shred the Brussels sprouts in a food processor fitted with the slicing blade, or with a sharp knife or mandoline slicer. Place the shredded Brussels sprouts in a large mixing bowl.
Peel the apples, and cut into quarters away from the core.
Shred the apples in a food processor fitted with the shredding blade, or with a julienne peeler or mandoline slicer fitted with the julienne blade. Place the apples in the bowl with the Brussels sprouts.
Toss the Brussels sprouts and apples together and cover with 1 cup water with the juice of 1 lemon added, to keep the apples from turning brown. Let the mixture sit for about 10 minutes.
Meanwhile, slice the green parts of the scallions, and measure out all remaining ingredients.
Drain the lemon water from the apples and Brussels sprouts,
Add the scallions, pecans, pomegranate seeds, cranberries and pumpkin seeds to the Brussels sprouts and apples and toss well to combine.
Pour dressing over all, and let sit for at least 30 minutes for the flavors to combine.
Notes
If you prefer a creamier dressing, double the dressing recipe.