Beat applesauce and white sugar together in a bowl. Add oats, soy milk, 1 tablespoon plus 1/4 teaspoon baking powder, vegetable oil, and sea salt; mix well. Fold raisins into oat mixture.
Pour oat mixture into the prepared pie pan; top with brown sugar and cinnamon. Refrigerate for 8 hours to overnight.
Preheat the oven to 350 degrees F (175 degrees C).
Bake in the preheated oven until oatmeal is firm, 35 to 50 minutes.