In a large mixing bowl combine yeast with warm water and 1 TBSP sugar. Stir to combine. Allow to sit approximately 5 minutes, until foamy.

In a medium saucepan, heat butter, 4 tablespoons of sugar and a pinch of salt over medium high heat.

When the butter melts, add the sour cream and heat to 105°.

Add butter and sour cream mixture into yeast mixture.

Whisk in egg and 1 cup of flour until smooth.

Gradually mix in the remaining flour with a wooden spoon until a soft dough forms. This will take at least 2 cups of flour. You want the dough to be sticky, but not tacky. Add in the extra 1/2 cup of flour if necessary to achieve the right consistency.

On a lightly floured surface, knead dough for 5 – 10 minutes, until it becomes elastic, adding more flour by teaspoon, if needed.

Form dough into a ball and place in a large, lightly oiled bowl. Roll dough around to coat entire surface with oil.

Cover bowl tightly with plastic wrap. Place in a warm, draft free area to rise for 1 hour, until doubled in size.

Make the filling by combining melted butter, cinnamon and sugar in a small bowl.

After the dough has risen, turn dough out onto a lightly floured surface.

Roll dough out to an approximately 18×14 inch rectangle.

Spread filling onto dough, leaving a border of about 1 inch all the way around.

Roll the dough, starting with the long edge, jellyroll style. Pinch the seams together.

Carefully place roll, seam side down, onto a baking sheet lined with parchment paper.

Bring ends of roll together, forming a circle shape. Press the ends together to completely seal the circle shape.

Cover dough with plastic wrap or a tea towel. Place in a warm, draft free place and allow to rise for 30 minutes.

Preheat oven to 375°

After the second rise, remove the plastic wrap and bake for 25 minutes, until cake is golden brown.

Immediately transfer cake to cooling rack. Allow to cool for 15 minutes.

To make the icing, whisk together powdered sugar, salt, vanilla, melted butter and milk until smooth.

After 15 minutes, turn cake over and insert plastic baby through the bottom of the cake.

Turn the cake right side up and place on parchment paper to catch any icing and sugar used to finish cake.

Drizzle icing evenly over cake, allowing it to ooze down the sides.

Before icing has a chance to set, sprinkle colored sugar in stripes around the cake.

Remove cake from parchment paper and place on platter for serving.