Friday, December 17, 2010

Walnut Coffee Christmas Log

STEP 1  - Coffee Cream
450g/8oz whole milk
120/4oz sugar
60/2oz corn starch
60/2oz unsalted butter, cold, cube
1 egg + 4 yolks
1 tbsp vanilla extract or dark rhum
1 tbsp instant expresso powder
Dissolve cornstarch in 1/4 of the milk,
combine rest of the milk with sugar and bring to boil,
while waiting whisk eggs in the cornstarch mixture,
pour 1/3 of the boiling milk over the eggs, then return milk and milk+egg mixture to the heat. Boil for about 1 minute whisking.
remove from the heat and whisk in butter, vanilla and coffee.
transfer to a cold container, press some plastic film directly on the cream and chill immediately.
STEP 2  - Chocolate Ganache
prepare this while the log is chilling
180g/6oz heavy cream
180g/6oz 70% chocolate (bittersweet),
grated or cut into small pieces
Bring cream to a boil, pour onto cut chocolate,
let sit for about one minute, then whisk to incorporate
the cream into the chocolate. 

STEP 3  - Walnut Sponge Cake (biscuit au chocolat)
6 large eggs, separated
4oz (120g) light brown sugar
8oz (320g) walnuts
2oz (60g) all purpose/plain flour
4oz (120g) sugar

Preheat your oven at 350F (390F). Butter and line a cookie sheet
with parchment paper.
Ground nuts and flour until powder but not oily.
Whip yolks with brown sugar until very light (about 5 minutes).
Whip whites with sugar until firm peak.
Fold whites into yolks and then the nuts/flour mix in three additions.
Spread on the cookie sheet and bake immediately for about 12 minutes.
Release from the pan as soon as possible. Remove carefully parchment paper.


If the cream is set and hard to spread whisk it before starting this step. Spread (or pipe) all the coffee cream onto the sponge cake. Roll the sponge cake into a log shape, use the parchment paper to keep it closed and refrigerate until the log is completely set and cold. At least 1hr. 

Unwrap the log over a cooling rack and cover with the warm ganache. Refrigerate until chocolate is set, then use a fork to draw grooves in the chocolate to imitate a tree bark.