Preheat a large nonstick skillet or griddle. Spread with 1 tbs butter. In a large bowl, whisk together the eggs, milk, cinnamon and vanilla. Dip each croissant half in egg mixture turning to coat. Add as many croissants as will fit onto skillet and cook until lightly browned, turning once, about 2 minutes per side. Remove from skillet and keep warm. Add remaining butter to skillet and repeat with remaining croissants. Serve topped with blueberry sauce. .
For The Sauce:
|Add blueberries to a pot with sugar and water and cook on medium heat, stirring frequently. Check for sweetness. If too tart, add more sugar and continue to cook. Once the sugar is melted, add 1 tbs water and puree 1/3 to _ of blueberry mixture in food processor. Return to pot and serve warm on French toast.|