1. Preheat oven to 350 and line muffin pans with baking cups to fill 9 holes. Coat with cooking spray.
2. Combine the pecans, sugar and flour in a large bowl and make a well in the center of the mixture. In a separate bowl, beat the eggs until foamy. Add the butter, then pour into the dry ingredients and stir until just moistened.
3. Spoon the batter into baking cups, filling 2/3 full. Bake for 20-25 minutes or until a toothpick inserted into the center comes out clean.
4. Remove from pans immediately and let cool. Top with whipped cream and sprinkle with cinnamon sugar.