Blueberry Streusel Coffee Cake

Name: Blueberry Streusel Coffee Cake
Prep time: 35 min
Cook time: 34 min
Total time: 1 h 9 min
Cuisine: American
Ingredients: 1/2 cup (65g) all purpose flour; 1/2 cup (112g) packed brown sugar; 3/4 tsp ground cinnamon; 1/4 cup (56g) unsalted butter, melted; Pinch of salt; 1 cup (130g) all-purpose flour; 1 1/4 tsp baking powder; 1/4 tsp salt; 1/2 cup (104g) sugar; 6 tbsp (84g) unsalted butter, room temperature; 1/4 cup (58g) sour cream; 1/4 cup (60ml) milk; 1 large egg; 1 tsp vanilla extract; 1 1/4 cups blueberries; 3/4 cup (86g) powdered sugar; 1-2 tbsp (15-30ml) milk; 1/4 tsp vanilla extract