Follow these steps to create your delightful Banana Walnut Cream Cake:

1. Preheat the Oven: Set your oven to 350°F (175°C), and grease and flour two 9-inch round cake pans.
2. Mix Dry Ingredients: In a large mixing bowl, whisk together flour, baking soda, and salt.
3. Cream Butter and Sugar: In another large bowl, cream the softened butter and granulated sugar until the mixture is light and fluffy.
4. Add Eggs and Bananas: Beat in the eggs one at a time, then mix in the mashed bananas until fully incorporated.
5. Combine Mixtures: Gradually add the dry ingredient mixture to the wet ingredients, alternating with the buttermilk, mixing until just combined.
6. Add Vanilla and Walnuts: Stir in the vanilla extract and fold in the chopped walnuts gently.
7. Pour into Pans: Divide the batter evenly between the prepared cake pans.
8. Bake: Place the pans in the preheated oven and bake for about 30-35 minutes or until a toothpick inserted in the center comes out clean.
9. Cool: Once done, remove the cakes from the oven and let them cool in the pans for about 10 minutes. Then, transfer to wire racks to cool completely.
10. Prepare the Cream Topping: In a chilled mixing bowl, whisk the heavy cream and powdered sugar until soft peaks form.
11. Assemble the Cake: Once the cakes are completely cooled, place one layer on a serving plate. Spread a layer of the whipped cream topping. Place the second layer on top and frost the top with the remaining whipped cream.
12. Garnish: For extra flair, sprinkle more chopped walnuts on top and the sides of the cake if desired.