PREP: Preheat the oven to 350 degrees F. Lightly grease a 9x13-inch metal baking pan with nonstick cooking spray (or you can line with parchment or foil and then grease for easy cleanup).
DRY INGREDIENTS: In a large bowl, whisk together flour, cinnamon, apple pie spice, nutmeg, baking soda, fine sea salt, and baking powder; set aside.
WET INGREDIENTS: In a medium bowl, add the oil, packed dark brown sugar, maple syrup, and heavy cream. Add in the vanilla and applesauce. Whisk until smooth.
COMBINE: Pour wet ingredients into the dry. Mix until just combined, being careful not to overmix the batter. The batter is very thick. Spread and then smooth the batter evenly in the prepared pan.
STREUSEL: Melt the butter in the microwave and then let stand at room temperature until cooled (don't add hot butter to the streusel -- it will make it greasy). In a separate medium bowl, whisk together one cup of flour, brown sugar, cinnamon, apple pie spice, and salt. Add the cooled melted butter and mix until the streusel is evenly combined and forms small clumps. Gradually add in the remaining 1/4 cup flour until larger clumps form. Sprinkle the streusel mixture evenly over the apple batter. Do not press the streusel into the cake. Use all of the streusel.
BAKE: Bake until the edges begin to pull away from the sides of the pan and a toothpick inserted in the center comes out clean (or with a few moist crumbs attached) about 35 to 40 minutes (My oven always takes 35 minutes). Cool completely in the pan before frosting.
GLAZE: Combine all the glaze ingredients in a small bowl. Start with 1 tablespoon apple cider and add more as needed until a thick glaze forms. Whisk with a fork until smooth. Drizzle over the individual pieces and serve.