Beat the eggs in a large bowl and add the cheese, 4 tablespoons sugar, 1 teaspoon vanilla extract, semolina and lemon zest into the eggs. Mix well with a fork or whisk until combined into a batter. Seal the bowl with plastic wrap and refrigerate for at least 2 hours until the batter has thickened.

Fill up a large pot with water and add ¼ teaspoon of salt. Place the pot over high heat and bring to a boil. Once the water is boiling make the dumplings. Transfer the dumpling mixture out of the refrigerator. Take about 1 ½ tablespoons of the mixture and roll it into a ball in between your palms. Gently place the ball into the boiling water. Continue shaping and adding about 4 more balls into the boiling water. Cook the balls until they rise to the surface. Cover the pot with a lid, reduce the heat to medium and continue cooking for another 6 to 8 minutes. Repeat the shaping cooking and draining of the dumplings with the remaining dumpling mixture in batches of about 4 dumplings at a time.

In the meanwhile, make the bread crumbs: Place the butter in a skillet over medium heat. Melt the butter, about 2 minutes. Add the breadcrumbs and constantly stir for about 6 to 8 minutes or until they become a deep golden brown. Transfer the breadcrumbs to a wide bowl. Add 1 tablespoon of sugar and 1 teaspoon of vanilla extract. Mix until combined well.

Roll each cooked dumpling in the breadcrumb and sugar mixture until coated completely. Serve with a dusting of cocoa powder and a dollop of sour cream.