Blueberry Babka Rolls

Ingredients

• 1 cup lukewarm water
• 2 1/4 tsp active dry yeast
• 4 - 4 1/2 cups flour
• 1/2 cup sugar PLUS a pinch
• 2 tsp salt
• 2 large eggs
• 1 large egg yolk (reserve the white for egg wash)
• 1/4 cup vegetable oil
• 4 Tbsp cornstarch
• 1/4 - 1/3 cup EACH white & brown sugar
• 1/4 tsp salt
• 1/2 cup water
• 2 cups fresh OR frozen blueberries
• 2 Tbsp lemon juice
• 1 reserved egg white
• pinch of salt
• 6 Tbsp flour
• 2 Tbsp powdered sugar
• 1/8 tsp EACH salt & baking powder
• 2 - 3 Tbsp cold butter
• 1/4 tsp vanilla
• 20 grams pistachios OR walnuts, chopped