Preheat oven to 350 degrees. With a mixer, beat the eggs with the sugar until slightly thickened and light in color, about 5-7 minutes. The mixture should almost double in size. This forms a ribbon when lifting the beaters.

Add the softened butter and vanilla extract; mix for two more minutes. Stir in the flour until just combined. Fold in the cranberries evenly.

Spread the batter into a buttered 9x13 inch pan. Bake for 40-50 minutes until lightly browned and a toothpick inserted near the center comes out clean.

Let cool completely before slicing into small pieces. Serve and enjoy!