Promised Land CSA » Rhubarb custard kuchen

Ingredients

• 1 3/4 cups all-purpose flour
• 1/2 teaspoon baking powder
• 1/8 teaspoon salt
• 3/4 cup unsalted butter
• 1 egg, beaten
• 1 tablespoon whole milk
• 1 1/2 pounds rhubarb, trimmed and cut into 1/2-inch pieces (about 4 cups)
• 3/4 cup whole milk
• 1 teaspoon pure vanilla extract
• 1 cup sugar
• 1 teaspoon cinnamon
• 2 tablespoons all-purpose flour