Preheat oven to 350 and grease an 8x8 pan with oil.
Make your flax egg. To a small dish add 2 tbsp flax meal with 1/4 cup water. Stir and let sit for a few minutes to form an "egg"
To a blender add the flax egg, apple sauce, soy milk, dates, baking powder, cinnamon, cardamom, ginger, nutmeg, and sea salt. Blend on high until smooth.
Add the blended mixture to a large mixing bowl along with the rolled oats, diced honeycrisp apple, chopped walnuts, and raisins. Stir until fully combined.
Add mixture to your pan and evenly press down. If you'd like, top with thinly sliced apple as garnish. Add to the oven and bake for 40 minutes.
Remove oatmeal from oven and let cool. Meanwhile, stir together the yogurt glaze ingredients. Once the oatmeal is cool, drizzle on top.
Enjoy immediately or cut into 9 slices and keep in an airtight container in the fridge.