Place the flour, sugar, butter, yeast, salt, milk, egg, yolks, vanilla and lemon zest in a food processor, blend until the ingredients form a smooth dough.

Cover the bowl with a clean dishcloth and let rise for 45 minutes.

Grease and flour a 10-inch ring springform pan

Drain the prunes reserving the extra Stroh liquid.

Turn the dough out onto a lightly floured work surface.

Divide the dough in half (use a kitchen scale for precise measurements)

Roll one half the dough out into a large rectangle and cut into 4 squares.

Brush the squares with butter, distribute 1/2 the prunes out over the squares then sprinkle evenly with 1/2 the cinnamon sugar.

Repeat with the other half of the dough.

Roll up the squares and place in the prepared baking pan. Cover the pan with a dishtowel and let rise for 45 minutes.

Preheat the oven to 350 degrees F.

Place the pan in the oven and bake for 45 minutes or until a knife inserted into the middle of the cake comes out clean.

Remove from oven. Let the cake rest in the pan for 15 minutes and then de-pan and place on a cooling rack positioned over a parchment paper lined baking sheet. Let cake cool completely.

Whisk together the powdered sugar with 4 tablespoons of the Stroh liquid from marinating the prunes until it forms a smooth, pourable glaze.

Pour the glaze evenly over the top of the cake. When the glaze has completely hardened, transfer the cake to a serving platter, slice and serve.