Preheat oven to 350 degrees F.In a microwavable bowl melt cashew butter and butter together for 30 seconds, stir until combined well.In a large bowl, whisk almond flour, salt and baking powder together. Pour the cashew butter mixture into the large bowl and stir to combine.Whisk the almond milk and eggs together then pour into the bowl and stir well.Break apart the frozen blueberries and gently stir into the batter.Line a loaf pan with parchment paper and lightly grease the parchment paper as well.Pour the batter into the loaf pan and bake 45 minutes or until a toothpick in center comes out clean.Cool for about 30 minutes then remove from pan.Slice and enjoy or toast each slice before serving.