Follow these simple steps to create your delicious Applesauce Coffee Cake:

1. Preheat Oven: Preheat your oven to 350°F (175°C). Grease and flour a 9×13-inch baking pan.
2. Mix Dry Ingredients: In a large bowl, whisk together the flour, granulated sugar, baking soda, baking powder, cinnamon, nutmeg, and salt.
3. Cream Butter: In another bowl, cream the softened butter until light and fluffy.
4. Add Wet Ingredients: Add the applesauce, eggs, and vanilla extract to the butter. Mix until well combined.
5. Combine Mixtures: Gradually add the dry ingredients to the wet mixture, stirring until just combined. Be careful not to overmix.
6. Add Nuts: If using, fold in the chopped walnuts or pecans for added texture.
7. Transfer to Pan: Pour the batter into the prepared baking pan and spread it evenly.
8. Top with Brown Sugar: Sprinkle the brown sugar over the top of the batter for a sweet, crunchy topping.
9. Bake: Place in the oven and bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
10. Cool: Remove from the oven and allow the cake to cool in the pan for 10-15 minutes before transferring to a wire rack.

These steps will guide you through the process of creating this incredible cake effortlessly.