Preheat the oven to 350 degrees Fahrenheit.
Place 1½ cups of rolled oats into a blender and blend until it turns into oat flour.
Sift the oat flour into a large mixing bowl and discard any pieces that are whole or not finely ground.
Sift in the almond flour and then add in the rest of the dry ingredients, and mix well.
Place the instant coffee in a small ramekin or measuring cup and dissolve with warm water.
In a medium sized mixing bowl, mix together the unsweetened plain coconut yogurt, honey, vanilla and coffee mixture. Lastly, whisk the eggs into the wet mixture.
Add the wet mixture in with the dry mixture.
Grease a loaf pan with vegan butter and then line the bottom with a sheet of parchment paper.
Pour the batter into the loaf pan and use a silicone spatula to scrape off any remaining batter from the bowl.
Top with walnut pieces and bake for about 50 to 55 minutes or until a toothpick comes out clean when inserted through the center of the loaf.
Let it sit a few minutes in the loaf pan, then very carefully lift it out using the parchment paper and transfer it to a cooling rack.
It's important to let the loaf cool completely before slicing into it because the loaf will continue to cook while coming down to room temperature. Cutting into it before its cooled down could possibly result in a mushy loaf.
Sift a confectioner sugar substitute over the top of loaf if desired. Slice and enjoy!