Prepare flax eggs in a large mixing bowl (by mixing water and flax seed and letting it rest for 5 minutes). Also preheat oven to 375 degrees F (190 C) and line an 8 x 8 inch baking dish or similar size pan.
To flax eggs, add olive oil, mashed banana, and maple syrup and whisk to combine. Next add brown sugar, salt, and cinnamon and whisk to combine.
Add almond milk and stir. Then add grated carrot and apple and stir.
Add oats, baking soda, almond meal (or flour), and gluten-free flour blend and stir to combine (see photo). You should have a thick but pourable batter - add more almond milk to thin if needed or more gluten-free flour or almond meal to thicken.
Pour into prepared baking dish and top with crushed walnuts. Bake for 40-45 minutes on a center rack or until deep golden brown and a toothpick inserted into the center comes out clean. When you press on the top, it shouldn’t feel too spongey, so don’t be afraid of over-baking! The GF blend just takes longer to bake than glutenous cakes.
Remove from oven and let rest in the pan for 15 minutes. Then gently lift out of the pan and let cool completely on a wire baking rack or flat surface. The longer it cools, the more airy and light the cake becomes.
OPTIONAL: While this is happening, you can make your frosting by adding soaked, drained cashews, coconut oil, coconut milk, lemon, maple syrup, and vanilla extract to a high-speed blender and blending on high until creamy and smooth. Taste and adjust sweetness or tartness as needed by adding more maple syrup or lemon juice, respectively. Then refrigerate to firm. Wait to frost the cake until frosting has thickened (about 2 hours), and the cake has cooled completely.
Store completely cooled leftovers loosely covered at room temperature up to 3 days, 5 days in the refrigerator (if frosted, it does need to be refrigerated), or in the freezer up to 1 month. Best when fresh.
*Nutrition information is a rough estimate calculated without frosting. *Recipe heavily adapted from my Carrot Apple Muffins!