Preheat the oven to 350°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.
In a large bowl, whisk together the Coffee Cake ingredients—flour, cinnamon, apple pie spice, nutmeg, baking soda, salt, and baking powder; set aside.
In a medium bowl, add the Coffee Cake ingredients—oil, dark brown sugar, maple syrup, and heavy cream. Add in the vanilla and applesauce. Whisk until smooth.
Pour wet ingredients into the dry. Mix until just combined; be careful not to overmix the batter. The batter is very thick. Spread and smooth the batter evenly in the prepared pan.
Melt the butter for the streusel in the microwave, then let stand at room temperature until cooled (don’t add hot butter to the streusel—that makes it greasy).
In a separate medium bowl, whisk together the Streusel ingredients—1 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 the streusel.
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, about 35–40 minutes. My oven always takes 35 minutes. Let cake cool completely in the pan before glazing.
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.
Video
Notes
Storage: For the best shelf life, glaze only the pieces you’ll eat right away and store the rest separately. Keep the cake wrapped at room temp for 2 days or refrigerate for up to a week. Microwave the glaze for 10 seconds before using. To freeze, wrap slices tightly and store in a freezer bag for up to 3 months. Thaw at room temp or in the fridge overnight before reheating.