To make the cake:
Preheat the oven to 350 degrees. Lightly grease a Bundt pan.
In a large bowl, whisk together flour, baking soda, salt, cinnamon, nutmeg, and ginger. In a separate bowl, whisk together applesauce, brown sugar, oil, vinegar, and vanilla. Pour the wet mixture into the dry mixture and whisk until just combined. Do not overmix. Gently fold in raisins and walnuts (see tip).
Fill the prepared pan evenly with batter. Bake for 40 to 45 minutes, or until a toothpick inserted in the center of the cake comes out dry with a few crumbs clinging to it. Rotate the cake halfway through baking time. Let the cake cool completely before unmolding.
To make the maple icing: In a medium bowl, whisk together powdered sugar, maple syrup, and 1 tablespoon water at a time, until it becomes a thick yet pourable icing.
To assemble the cake: Once the cake is completely cooled, run a knife around the inside edges of the pan to loosen. Gently unmold the cake and place on a wire rack over parchment paper or a baking sheet. For a less sweet dessert, very lightly drizzle some of the glaze over the cake. If you prefer a sweeter dessert, be more generous with the glaze. Regardless, you may not need to use all of the glaze. Transfer to a platter and serve.
Chloe’s Tip: How to prevent raisins from sinking during baking
To keep raisins, nuts, or chocolate chips from sinking to the bottom of a cake during baking, toss the add-in's in 1 tablespoon flour before adding them to your batter. This will ensure even distribution throughout the cake.
*For a gluten-free alternative, substitute gluten-free all-purpose flour plus 1 teaspoon xanthan gum.