Blueberry breakfast brioche

Ingredients

• 1/4 cup full-fat milk, warmed to room temperature
• 1 cup sugar
• 2 tbsp active dried yeast
• 6 free range eggs
• 2 free range egg yolks
• 2 cups plain flour
• 2 cups high-grade flour
• 2 tsp salt
• 250 g butter, at room temperature
• 250 g fresh blueberries
• Egg wash
• 1 egg yolk mixed with a dash of salt and 1 Tbsp cream