Preheat oven to 350ºF and line a standard loaf pan with parchment paper.
Prepare the streusel topping by mixing all ingredients into a small bowl until a crumble forms. Set aside.
Combine all of the dry ingredients in a medium-sized bowl. Set aside.
In a large bowl, cream together brown sugar, oil, and vanilla. Add the peanut butter, grated apples, and banana. Mix again until combined. Add eggs and gently mix until combined. Lastly, add the almond milk until combined.
Slowly add dry ingredients to the wet ingredients and mix until smooth.
Transfer the batter to the loaf pan and top with the streusel you made earlier.
Bake for 50-60 minutes or until a toothpick comes out clean. Remove the bread from the oven, let it rest for a few minutes, and then run a knife along the edges of the bread. Gently lift the parchment paper up and transfer the bread to a cooling rack. Let it cool for 15-20 minutes.