Spray a miniature muffin tin (or a standard-size muffin tin) with cooking spray and set aside.
Place egg, melted butter, and almondmilk in a large blender. Puree until smooth.
Break graham crackers into pieces and place in blender. Blend until smooth.
Add flour, sugar, baking powder, and salt to the blender. Pulse a few times, just until all ingredients are combined. Be careful not to overmix or you will end up with tough muffins.
Pour batter into prepared muffin tins.
Bake for 10-15 minutes for miniature muffins (or about 15-20 minutes for larger muffins), or until a toothpick inserted in the center comes out clean.