In a sealable container, add the cashews, water and almond milk. Cover with a lid and refrigerate overnight.
The next day, dump the entire cashew/water/milk mixture into a high-speed blender (I used my Vitamix). Add the vanilla extract, stevia extract and salt. Blend on high speed until completely smooth.
Pour in the melted coconut butter and blend again.
Add the protein powder and matcha powder and blend one last time.
Line an 8x8" brownie pan with parchment paper both ways. Scoop the mixture into the prepared pan and spread it out. Tap the pan on the counter a few times to help get rid of air bubbles. Use an offset spatula if you want to spread out a perfectly flat top. Cover the pan and refrigerate overnight. Slice, serve, and enjoy!