Step 2

Make the Frosting: Place the cashews, syrup, nondairy milk or water, vanilla extract and salt in the bowl of a high-speed blender or food processor. Blend on high or process until the mixture is mostly smooth, about 2 minutes in a high-speed blender or about 4 minutes in a food processor.

Step 3

With the machine running, drizzle in the coconut oil. Continue blending until the frosting is smooth and emulsified. Transfer it to an airtight container and chill for at least 2 hours. It will keep in the fridge for up to four days.

Step 4

Make the Cake: Preheat the oven to 350°F. Grease and flour a 9-inch springform cake pan.

Step 5

Sift the flour into a large mixing bowl; stir in the sugar, baking soda, baking powder and salt.

Step 6

In another large mixing bowl, stir together the banana, yogurt, nondairy milk, oil, lemon juice and vanilla extract. Fold the dry mixture into the wet mixture until the batter is evenly mixed and no flour remains at the bottom. A few lumps in the batter are fine.

Step 7

Bake the cake until the top is golden and firm to the touch and a toothpick inserted into the center comes out clean, 35 to 40 minutes. Remove the cake from the springform pan and allow it to cool completely before frosting.

Step 8

Frost the top of the cake and then garnish with the nuts, if using.