Activate the yeast by mixing warm milk with granulated sugar, then sprinkle the yeast on top and let it sit for 5-10 minutes until foamy.

In a large mixing bowl, combine melted butter, eggs, and salt. Add the foamy yeast mixture and stir until well combined.

Gradually add flour, one cup at a time, mixing until a soft dough forms. Knead the dough on a floured surface for about 5-7 minutes until smooth and elastic.

Place the dough in a greased bowl, cover with a clean cloth, and let it rise in a warm place for about 1 hour until doubled in size.

Prepare the filling by mixing brown sugar and ground cinnamon in a small bowl. Set aside.

Once the dough has risen, punch it down and roll it out on a floured surface into a large rectangle, about 1/4 inch thick.

Spread softened butter evenly over the dough, then sprinkle the cinnamon-sugar mixture over the buttered dough.

Starting from one long edge, tightly roll the dough into a log and pinch the seams to seal. Form the log into a circle and pinch the ends together.

Place the ring on a greased baking sheet, cover, and let it rise for another 30 minutes. Preheat the oven to 350°F (175°C).

Bake the king cake for 25-30 minutes until golden brown. Let it cool on a wire rack.

Prepare the glaze by whisking together powdered sugar, milk, and vanilla extract until smooth. Drizzle over the cooled cake and sprinkle with colored sprinkles.