Preheat the oven to 350 degrees F (175 degrees C) or 325 degrees F (165 degrees C) according to package directions and baking pan material.

Combine cake mix, water, and egg in a bowl; pour into pan size, shape, and material of your choice. Bake according to package directions and pan size, shape, and material, 24 to 37 minutes. Cool completely, about 1 hour.

Meanwhile, place pudding mix in a large bowl; whisk in eggnog for about 2 minutes. Refrigerate pudding until gingerbread cake is cool and ready to assemble trifle.

Whip cream in a separate large bowl until stiff peaks are just about to form. Beat in sugar and vanilla until peaks form.

Crumble 1/2 gingerbread cake into a trifle or large glass bowl. Spread 1/2 eggnog pudding over cake, then spread 1/2 whipped cream on top of pudding. Repeat layers with remaining 1/2 each gingerbread cake, eggnog pudding, and whipped cream. Refrigerate 6 hours to overnight. Sprinkle top with cranberries and cookie crumbs before serving.