1Preheat oven to 325. Spray mammoth muffin pan or use paper baking cups.
2Whisk together flour, baking soda, baking poeder and salt. Set aside.
Cream together margerine and sugar. Add eggs and mix well. Stir in sour cream and vanilla until well combined.
3Gently fold in floue a third at a time adding blueberries along with the last third of flour mix just until blended. DO NOT overmix.
4Evenly fill 12 muffin cups (should be 3/4 full). Sprinkle with coarse sugar and cinnamon, if desired.
Bake at 325 for 28-35 minutes until toothpick inserted comes out clean. Cool on rack 10 minutes. Remove from pan. Serve warm or cold.