PREP: Set out the cream cheese to warm to room temperature. Preheat the oven to 350 degrees F. Line an 8x8-inch baking pan with parchment paper -- otherwise your cake will likely not come out easily. Greasing and flouring the pan isn't enough -- this batter is sticky and needs parchment paper. Foil will affect baking, so I don't recommend foil.
WET INGREDIENTS: In a large bowl, stir together the applesauce, coconut oil (measured when completely melted and then cooled back to room temperature See Note 1), large egg, vanilla extract, and brown sugar. Stir until completely combined and smooth.
DRY INGREDIENTS: Add the baking soda, baking powder, salt, cinnamon, allspice, and nutmeg (you can use a little less or more, depending on your preference). Add in the oat flour. (See Note 2.) Add in the chopped pecans and raisins if desired. Mix ingredients until completely combined and smooth.
BAKE: Transfer batter to prepared 8x8-inch pan. Bake for 28-33 mins at 350 degree F oven or until a fork when inserted comes out clean. Be careful to not-over bake, as it will make this cake less tender and less flavorful. Allow to cool completely before frosting.
FROST: Place softened cream cheese in a large bowl (give it ample time to set out so your frosting isn't chunky). Using a hand mixer, beat with the vanilla until smooth. Add in the salt and slowly add in the powdered sugar (beating in between additions) until smooth and creamy and your desired consistency has been met. If it is too thick add in a little bit of milk. If you'd like a more tangy or soft frosting, only add 1 and 1/4 cups powdered sugar. For a sweeter, thicker frosting, add closer to 1 and 3/4 cups.
DECORATE: Frost the completely cooled cake evenly with the frosting. If desired, top the frosting with the chopped pecans.
STORAGE: Store cake at room temperature, covered with plastic wrap. Applesauce Cake is best when used within 1-2 days. Freeze (un-frosted) pieces for up to 3 months; thaw at room temperature and then frost. Frosted cake doesn't freeze and thaw well.