Aunt Anne's Coffee Cake

INGREDIENTS

• 2 cups all-purpose flour
• 3/4 cup white sugar
• 2 teaspoons baking powder
• 1/2 teaspoon salt
• 1/2 cup butter
• 1 egg
• 3/4 cup milk, or as needed
• 1 1/2 teaspoons vanilla extract
•  
• 1/4 cup all-purpose flour
• 2/3 cup white sugar
• 1 teaspoon ground cinnamon
• 1/4 cup butter