The day before you assemble the bombe, prepare the chiffon cake and allow to cool. Prepare the pastry cream, cover with plastic or waxed paper and refrigerate to set. (To do this quickly pour it into a shallow dish.) Mix the heavy cream into the cold pastry cream with a wire whisk or spatula. Prepare the ganache and refrigerate until cool and thick enough to cover the dessert.

When you are ready to assemble the dessert, prepare the syrup: Bring the sugar and 3 tablespoons water to a boil in a small saucepan, reduce the heat to medium, and simmer for 3 minutes. Remove from the heat. Mix the remaining tablespoon water with the coffee and add to the syrup. Add the liqueur. Let cool.

Turn the cake out of the bowl onto a serving plate and peel off the foil. Slice the cake horizontally into 4 layers.

Remove the top 3 layers and brush the bottom one with syrup, spread with 3 tablespoons of the pastry cream, sprinkle with some almonds. Replace the next layer and repeat until you place the final layer on top.

Frost with the ganache and sprinkle with almonds all over.

Refrigerate overnight or cool quickly for 30 minutes in the freezer.