Preheat your oven: Start by preheating your oven to 350°F (175°C). Prepare an 8x3 inch round cake pan by greasing it or lining it with parchment paper. This prevents the cake from sticking.
Beat the eggs and sugar: In a stand mixer, combine 3 eggs and 1 cup of granulated sugar. Beat this mixture on high speed until it doubles in volume, achieving a light and airy consistency. This process generally takes about 5 minutes.
Add the avocado oil: With the mixer still running, slowly add in 1/2 cup of avocado oil. Mix for another minute until combined evenly.
Prepare the dry ingredients: In a separate bowl, whisk together 2 1/2 cups of sifted all-purpose flour, 2 tsp of baking powder, 1 tsp of baking soda, 1 tsp of cinnamon, 1/2 tsp of pumpkin spice, and 1/4 tsp of ginger powder. This helps ensure that the leavening agents are evenly distributed.
Combine the mixtures: Gradually fold the dry mixture into the wet ingredients using a spatula. Mix gently to avoid deflating the egg mixture. Once combined, fold in 2 cups of diced persimmons and 1 cup of chopped walnuts.
Pour and bake: Pour the batter into the prepared cake pan. Bake in the preheated oven for 50-60 minutes or until a toothpick inserted in the center comes out clean. While baking, the cake will rise beautifully.
Cool the cake: Let the cake cool in the pan for about 15 minutes before transferring it to a wire rack to cool completely. This step is crucial to maintain the cake’s texture.
Prepare the whipped cream: While the cake is cooling, whip 1 cup of heavy whipping cream with 1 tbsp of maple syrup until soft peaks form. Keep this whipped cream chilled until you're ready to serve.
Make the persimmon jam: In a blender, combine 1 cup of diced persimmon, 1/2 tsp of pumpkin spice, and 1 tbsp of maple syrup. Blend until smooth, then transfer to a jar for serving.
Assemble and serve: Once your cake has fully cooled, spread the whipped cream generously on top. Layer with the persimmon jam, and for a beautiful finish, garnish with fresh persimmons and walnuts. Enjoy your creation!