Almond Croissant Cinnamon Rolls

Name: Almond Croissant Cinnamon Rolls
Ingredients: 1 cup whole milk; 4 tablespoons unsalted butter (cubed and very soft); 1/2 teaspoon almond extract; 3 1/2 cups all-purpose flour (divided); 1 packet (0.25 oz rapid rise yeast); 3 tablespoons granulated sugar; 1/2 teaspoon salt; 1 large egg (at room temperature); 1 cup light brown sugar; 1/2 tablespoon ground cinnamon; 1/2 cup unsalted butter (very soft); 1 cup powdered sugar; 1 teaspoon almond extract; 1-2 tablespoons milk (as needed); 1/2 cup toasted slivered almonds