Stuffed Challah Hedgehogs

Name: Stuffed Challah Hedgehogs
Ingredients: 3/4 cup warm water (105 to 110 degrees F); 2 1/4 teaspoons active dry yeast; 1/4 cup plus 1 teaspoon granulated sugar; 3 1/4 cups all-purpose flour, plus more for dusting; 1 teaspoon kosher salt; 1/3 cup flavorless oil, like canola or vegetable, plus more for the bowl; 2 large eggs; 3/4 cup granulated sugar; 1/4 cup unsalted butter, at room temperature; 1/8 teaspoon kosher salt; 1 large egg, separated; 1/4 teaspoon vanilla extract; 1 1/2 cups pecan flour (if you can't find pecan flour, pecans pulsed until fine and dry in a food processor); Black sesame seeds, for decorating; 1 1/2 cups powdered sugar; 1/2 teaspoon almond extract; 5 to 6 teaspoons whole milk; Slivered almonds, for decorating