Preheat your oven to 350°F (175°C). Grease and flour a 9-inch square baking pan or bundt pan. For extra flavor, consider using a light dusting of cinnamon-sugar instead of flour.
In a medium bowl, whisk together flour, baking soda, baking powder, salt, and all spices until completely uniform.
Using a stand mixer or hand mixer, beat the butter and sugar together on medium-high speed until light and fluffy, about 3-4 minutes.
Add eggs one at a time, beating well after each addition. Scrape down the sides of the bowl as needed. Mix in vanilla extract.
Gradually add the flour mixture to the butter mixture, alternating with applesauce in three additions, beginning and ending with flour. Mix on low speed just until combined after each addition.
If using, fold in nuts and/or dried fruit by hand using a rubber spatula.
Pour the batter into the prepared pan and smooth the top. Bake for 45-50 minutes, or until a toothpick inserted in the center comes out clean or with just a few moist crumbs.
Allow the cake to cool in the pan for 15-20 minutes, then turn out onto a wire rack to cool completely. For optimal flavor development, wait at least 4 hours before serving.