Maple walnut roulade

I love maple. I'm always a bit sad when sugaring-off season is over, even if it means the weather is above 0℃ on a regular basis. This year I didn't make it to the sugar bush at all, but luckily I still have lots of syrup from last year. I have lots of walnuts too: I won over a kilogram of fantastic walnuts from a giveaway on Evelyne's blog, Cheap Ethnic Eatz. They arrived when I was in Toronto, and I've been trying to decide what to do with them ever since I got home. As usual, I have lots of ideas, but can only eat so many sweets! Watch for more walnutty goodness around these parts, as this recipe only used about a half-cup.

I decided to make a small rolled cake, substituting walnuts for the almonds. For the filling, I went with mascarpone and maple syrup, because that is one of the loveliest combinations ever. I was worried about the maple syrup thinning out the filling too much, so I reduced mine, ending up with maple fudge. Now, maple fudge is a very good thing, but not what I wanted here. I used it anyway and it dissolved in the mascarpone, but I don't think reducing it was necessary, so I've adjusted for that below. I also couldn't resist garnishing with a few maple candied almonds. 3 components seems like a lot, but this actually took less than an hour to mix, bake, cool and roll. A quarter sheet pan measuring 33cm x 24cm (13" x 9.5"), made enough for 4 servings, so double everything if you want to make it in an 11" x 17" pan and serve 8. Measurements are in grams, as the amounts were small.

Candied walnuts

½ cup walnut halves

2 tablespoons pure maple syrup

a pinch of salt, optional

Preheat oven to 275℉. Combine walnuts and syrup and salt, if using and spread on a parchment or foil lined baking sheet. Bake about 30 minutes, stirring every 10 minutes. Cool.

Walnut cake
Adapted from The Cake Bible, Rose Levy Berenbaum
18 grams toasted walnuts
10 grams cake flour
2 large eggs
55 grams sugar
a few drops vanilla extract
¹⁄₈ teaspoon cream of tartar

1. Grease quarter sheet pan and line with parchment. Grease again and flour. Increase oven temperature to 450℉. 
2. Combine walnuts, cake flour and about a tablespoon of sugar in a food processor and grind finely. 
3. Separate 1 egg and place the white in a small mixing bowl. Using a hand mixer, beat on medium speed until frothy, then add the cream of tartar. Once soft peaks form, add a tablespoon of the remaining sugar and beat until stiff peaks form. Set aside.
4. Place the yolk and the second whole egg in a small mixing bowl, along with the remaining sugar. Using the hand mixer (don't bother cleaning the beaters), beat on high speed for about 4 minutes, until thick, fluffy and tripled in volume. Beat in the vanilla.
5. Add the ground walnut mixture and fold in, using a spatula. When almost uniform, fold in the egg white. Spread evenly on the prepared pan and bake for about 7 minutes, until a tester comes out clean and the cake is golden and springs back when you touch it.
6. Loosen the edges and flip the cake, paper and all, onto a clean tea towel. Carefully peel off the parchment paper and sift a thin layer of icing sugar over the top. Roll it up from the short end, towel and all. Cool on a rack.

Maple Mascarpone Filling

Adapted from the Cake Bible

1-227 gram container mascarpone (1 cup)

¼ cup pure maple syrup

⅓ cup whipping cream

Combine all ingredients in a medium bowl, and beat briefly, by hand or with a mixer until mixture thickens. Refrigerate while waiting for the cake to cool.

To assemble cake:

Unroll cake, remove towel and spread mascarpone filling evenly with a metal spatula. Leave the last inch of cake bare, as rolling will push the filling to the end. You won't need all the filling, unless you want a ridiculously full cake like mine. Re-roll and trim ends on the diagonal. Refrigerate, covered, until serving time. Garnish with candied walnuts.

Update:
I took the cake to some overworked friends, who said that it looked like a giant Twinkie. Exactly what I was aiming for...