Preheat the oven to 350°F. Grease a muffin pan with a bit of vegetable oil and a paper towel. Or spray with nonstick cooking spray.
Add a few graham crackers to a bag and seal tightly. Crush the crackers with your hands or the side of a rolling pin. All crumbs should be very small bite-size pieces.
Add 1 cup of graham cracker crumbs, 1 cup whole wheat flour, ½ cup brown sugar, 1 tsp cinnamon, 1 tsp baking powder, ½ tsp baking soda, and ¼ tsp salt to a large bowl. Mix together until even.
In a separate medium bowl, beat one egg and add the 1 cup milk, ¼ cup vegetable oil, and 1 tsp vanilla extract. Mix together.
Pour the wet ingredients into the dry ingredients. Mix together until just combined (do not overmix).
Add approximately ¼ cup batter to each muffin cup. Sprinkle the tops with 1 tsp crushed graham crackers, gently pressing the crackers into the batter.
Bake for 20-22 minutes, or until tops are dark golden brown and a toothpick comes out clean when poked through the center. Let cool 5 minutes, then transfer to a wire rack to cool completely.