Combine the almond milk and apple cider vinegar in a small bowl.
Preheat oven to 325 degrees. Line a 12-cup muffin tin with muffin cups.
Dice the strawberries and set aside.
Mash the bananas, and transfer to a mixing bowl.
Add in vanilla yogurt, honey, vanilla and almond milk mixture. Mix by hand just until combined.
Stir in the oat flour, baking powder and salt. Mix with a wooden spoon just until combined. Fold in the strawberries and stir until evenly combined.
Spoon the batter into the muffin cups. Bake for 10 minutes.
Meanwhile, make the cashew crumble: Chop the cashews and place in a small bowl. Add in the oats and brown sugar, and stir to combine.
Remove the muffins from the oven, and spoon the cashew crumble on top. Bake for another 15 minutes, or until a toothpick comes out clean in the center of the muffins.
Transfer to a cooling rack to cool down before enjoying.