In a large mixing bowl, combine sour cream, melted butter, salt, and granulated sugar. Sprinkle yeast over warm water and stir; let sit for about 10 minutes until bubbly and foamy. Mix the yeast into the sour cream mixture.

Add beaten egg and all-purpose flour to the yeast mixture. Stir until a soft, slightly sticky dough forms. Knead for about 5-7 minutes until smooth and elastic.

Shape the dough into a ball and place it in a greased bowl. Cover with a kitchen towel and let rise in a warm place for 1-2 hours until doubled. Punch down to release air bubbles.

In a bowl, beat cream cheese, beaten egg, brown sugar, cinnamon, vanilla extract, and chopped pecans until creamy and well blended.

Roll out the dough into an oval shape about 1/4 inch thick. Spread the pecan filling evenly, leaving a border. Carefully roll the dough from one long side to the other, pinching the ends to create a ring.

Place the shaped dough on a parchment-lined baking sheet, cover, and let rise for another hour until puffy.

Preheat oven to 350°F. Bake for 25-30 minutes until golden brown. Cool on a wire rack.

Whisk together powdered sugar, melted butter, vanilla extract, and milk until smooth. Frost the top of the cake while it’s still slightly warm.

While the glaze is wet, sprinkle colorful sanding sugars on top. Slice and serve warm or at room temperature.