Preheat the oven to 350 degrees Fahrenheit (175°C). Lightly butter a 9x13 inch baking pan.

Beat the 3 eggs with the 2 cups sugar in a large bowl using an electric mixer. Continue beating for about 5-7 minutes, until the mixture is slightly thickened, light in color, and has almost doubled in size, forming a ribbon when the beaters are lifted.

Add the 3/4 cup softened butter and 1 teaspoon vanilla to the egg mixture. Mix for an additional two minutes until well combined.

Stir in the 2 cups all-purpose flour until just incorporated and no dry streaks remain.

Fold in the 12 oz fresh cranberries until evenly distributed throughout the batter. The batter will be very thick.

Spread the thick batter evenly into the prepared 9x13 inch baking pan, pressing it gently to form a flat layer.

Bake for 40-50 minutes, or until the cake is very lightly browned on top and a toothpick inserted near the center comes out clean.

Let the Cranberry Christmas Cake cool completely in the pan before cutting into slices.