In a large bowl, dissolve one package of cranberry gelatin in 2 cups of boiling water. Stir well until completely dissolved, about 2-3 minutes. Add 1 cup of cold water and stir. Pour half of this mixture into your 9x13 inch baking dish. Refrigerate for 30-45 minutes, or until set but still slightly sticky to the touch.

Dissolve the lemon gelatin in 1 cup of boiling water in another bowl. Stir until fully dissolved. Set aside to cool to room temperature.

In a separate bowl, using an electric mixer or whisk, beat the softened cream cheese until smooth. Gradually beat in the sour cream (or Greek yogurt), granulated sugar, and vanilla extract until the mixture is light and fluffy. Slowly add the cooled lemon gelatin mixture to the cream cheese mixture, beating until thoroughly combined and smooth.

Once the first cranberry layer is set, carefully spoon the creamy lemon mixture over it, spreading evenly. Refrigerate for another 30-45 minutes, or until this layer is firm.

In the bowl with the remaining half of the first cranberry gelatin mixture, stir in the entire can of whole berry cranberry sauce. Mix well to combine.

Gently pour the cranberry sauce mixture over the set creamy layer. Return the dish to the refrigerator for at least 4 hours, or preferably overnight, to allow all layers of the Layered Cranberry Gelatin to set completely and firm up.

Once fully set, cut the Layered Cranberry Gelatin into squares or use a decorative cookie cutter for a fun presentation. Serve chilled.