Mont blanc is traditionally a French dessert, featuring a puree of chestnut piped over whipped cream and topped with powdered sugar to resemble a snow-capped mountain; fun fact, mont blanc is French for white mountain. This dessert is popular in both France and Japan, and other varieties use sweet potatoes, shiro an or azuki beans instead of chestnut. For my rendition, I chose to use sweet potatoes, because I really love the airy and light a sweet potato puree can be, and how beautifully it can pair with butter.
While mont blanc is typically just the puree on cream with puree, a lot of bakeries serve it on top of something, whether it be a piece of pate sucre or a small cake. I like to pipe my mont blanc onto financier, and I am more than comfortable with making a sweet potato financier. For those of you who do not know what a financier is, they are French brown butter-almond spongecakes that are reminiscent of gold blocks. The name is rumored to come about from that fact, plus the dessert being popular with French bankers. Being an accountant, I thought it would be a fun play on words, being a a financier i.e. practitioner of finance, making a financier. Just humor me and laugh. Please. Don’t make this awkward.
For the financier, I used equal parts flour, almond meal, and sweet potato puree. Normally, you would use three parts almond meal to one part flour, but I needed the extra flour there so that the glutens can bind the batter, while the sweet potato puree will lighten it up. I also used the skins to make sweet potato croquants, which is like a thin, crunchy toffee, and to echo the pairing of butter and potatoes, I topped the dessert with a butter snow, using tapioca maltodextrin and butter, in lieu of the powdered sugar, since I did not want to cake my dessert in that. This recipe can make up to twenty four mini, rectangular mont blancs.
For sweet potato puree:
1 large sweet potato
a pinch of salt
Rinse the sweet potato. Peel and reserve the skins. Cube. Boil the sweet potato until tender. Puree and pass through a strainer.
For potato croquant:
Potato skins
1/4 cup granulated sugar
2 tablespoons canola oil
a pinch of salt
1/2 teaspoon vanilla extract
Combine ingredients and lay out on a lined baking sheet. Bake at 350 degrees F for 12 minutes. Cool completely before removing from the baking sheet.
Sweet potato financier:
3 egg whites
3/4 cups granulated sugar
1/3 cup sweet potato puree
1/3 cup all-purpose flour
1/3 cup almond meal; sifted
1/2 teaspoon baking powder
1/2 cup browned butter
Whip egg whites with granulated sugar until they form stiff peaks. Fold the brown butter into the sweet potato puree. Combine sifted flour and almond meal. Fold together all of the ingredients. Pour into brown butter-lined baking molds and bake at 350 degrees F at 25 minutes. Cool completely before unmolding.
Chantilly:
1/4 cup heavy cream
2 tablespoons granulated sugar
a pinch of sugar
1/2 teaspoon vanilla extract
Combine ingredients and whip to stiff peaks.
For the sweet potato mont blanc topping:
Sweet potato puree
Mizuame
a pinch of salt
Dilute the remaining puree with mizuame until it is loose enough to pass through the prongs in a fork. Season. Transfer into a piping bag with a grass tip.
Butter snow:
4 tablespoons unsalted butter
1/2 cup tapioca maltodextrin
Puree ingredients together. Freeze solid.
Assembly:
Top the cakes with chantilly and pipe the puree in a criss-cross motion over the cream. Use an offset spatula if necessary to level off the sides. Grate the butter snow over the puree. Top with the croquant to garnish.