Morning Sour Cream Coffee Cake

Ingredients

• ***For the streusel:***
• 1 cup brown sugar
• 1/2 cup sugar
• 1/4 teaspoon salt
• 1 1/2 tablespoons cinnamon
• 1 cup butter, melted
• 2 1/2 cups flour
• ***For the cake:***
• 4 large eggs
• 1 1/2 cups sour cream, divided
• 1 tablespoon vanilla extract
• 2 1/4 cups all-purpose flour
• 1 1/4 cups sugar
• 1 tablespoon baking powder
• 3/4 teaspoon baking soda
• 3/4 teaspoon salt
• 12 tablespoons butter, softened
• ***For the icing:***
• 1/4 cup butter, melted
• 2 cups powdered sugar
• 1 teaspoon vanilla extract
• 1/2 teaspoon kosher salt
• 1/4 cup half-and-half or milk, plus more, to taste