I don’t like using the term copy cat, I prefer to say that is an homage to my favorite cake, actually one of the best cakes I have ever had. I first got this cake many years ago at the Watergate Pastry Shop in Washington DC. I was smitten and it was love at first bite. The softest, lightest and most tender vanilla cake, a creamy white Chocolate mousse filling, frosted in whipped cream. At the time I didn’t know what the subtle flavor was that made it so distinct, after some research I found out it was Grand Marnier or Cointreau.
I have been thinking about this cake and wishing I could make a trip to DC for the express purpose of buying it, well that’s not practical and instead I decided to try my hand at making it. The recipe I always use for a yellow or vanilla cake Tender Yellow Cake, I have posted many times, its super light, a cross between a chiffon and a yellow or vanilla cake, I knew this would work well. Years ago I posted a recipe for white chocolate mousse filling, when I made it then it was pretty seamless, this time not so much, but after some MacGyver like moves it actually came out pretty perfect. I recently received some vanilla beans and powdered vanilla seeds from a company called Native Vanilla and I have to say the beans are far superior to any vanilla beans I have ever used. They are so fresh, plump, loaded with vanilla seeds and so so fragrant. The vanilla seeds made this mousse incredible, additionally it is flavored with Cointreau. The cake is frosted with my go to stabilized whipped cream also flavored with Cointreau and vanilla.
It has been a few years since I had the Watergate cake but I think that this is pretty darn close to my recollection of the flavors and textures.
White Chocolate Mousse
1 1/2 C heavy cream divided
2 scant tsp unflavored gelatin
6 oz white chocolate (chips or bar cut into small pieces)
1 vanilla bean split and seeds scraped (highly recommend Native Vanilla)
1 tbs Cointreau or Grand Marnier
Bloom the gelatin by placing in a small bowl and add 2 tbs cold water, stir and let sit. Heat 1/2 cup heavy cream to scalding. Put the white chocolate into your food processor and pulse to break into very fine pieces, mix the gelatin in the hot cream scrape in the vanilla seeds pour over the chocolate and process until smooth. Scrape into a bowl and let cool. While cooling whip the remaining 1 cup cream until stiff. Whisk into the white chocolate and liquor, cover and refrigerate until ready to use. The mixture was thick and a little lumpy so I spooned it into the food processor and pulsed until smooth.
NOTE:The mousse was really thick so before filling the cake I whipped 1/2 cup heavy cream and folded it in. Judge for yourself how it is. You could decrease the gelatin but I wanted it to have structure so it would hold up in between the cake layers. It was the perfect texture and consistency after folding in the additional whipped cream.
After frosting the cake I decorated the top with shaved white chocolate curls.