To make the lavender simple syrup: In a small saucepan, combine lavender sugar and water. Bring to a simmer, stirring to dissolve sugar. Remove from heat and let cool to room temperature. Stir in lavender extract and strain into a glass jar. Store in the refrigerator.
To make sangria, fill a glass with ice. Add lavender simple syrup, blueberries, and prosecco. Stir gently and enjoy!
To make a pitcher: Add a pint of blueberries and 1/3- 1/2 cup simple syrup to a pitcher. Add one 750 ml bottle or prosecco. Stir and serve over ice.
*I make lavender sugar by mixing a couple tablespoons of food grade dried lavender buds with about 1 cup of sugar in a jar, and letting it sit at least overnight.