Rhubarb and Rye Streusel Muffins with Rhubarb Curd

These rhubarb and rye streusel muffins are tender, lightly sweet, and balanced with the earthy depth of rye flour and the bright tartness of fresh rhubarb. Topped with buttery streusel and served alongside a silky rhubarb curd, they make a beautiful springtime breakfast or brunch treat that feels special without being overly rich.

• 3 tablespoons all-purpose flour
• 3 tablespoons rye flour
• 2 tablespoons granulated sugar
• 2 tablespoons light brown sugar
• 1/4 teaspoon ground cinnamon
• 3 tablespoons butter, melted

• 1 large egg
• 1/4 cup light brown sugar
• 1/4 cup white sugar
• 5 tablespoons salted butter, melted and cooled
• 1 cup sour cream
• 1 cup all-purpose flour
• 1/2 cup rye flour
• 1 1/2 teaspoons baking powder
• 1/4 teaspoon baking soda
• 1 cup diced rhubarb

• 1/2 pound rhubarb, cut into 1/2-inch pieces
• 1/4 cup plus 3 tablespoons sugar
• 1/4 cup water
• Juice from 1/2 lemon
• 2 egg yolks
• 1 whole egg
• 4 tablespoons salted butter, cut into pieces