A bûche de Noël--a cake decorated like a yule log--is a traditional dessert served around Christmastime in France, Belgium, Canada and some other French-speaking countries. Our gluten-free recipe, which is just as tasty served cold as it is at room temperature, is lighter than air. The chocolate brown-butter génoise cake is easy to roll up and it's covered with a billowy espresso-spiked 7-minute frosting. We've substituted agave nectar for white sugar in the frosting. It's pretty garnished with meringue mushrooms and sugared rosemary.
Make Ahead Tip: Prepare through Step 9 and hold at room temperature for up to 2 hours or refrigerate, uncovered, for up to 1 day.
Equipment: 12-by-16 1/2-inch rimmed baking sheet
Tips: Check to be sure the brand of extract you select is labeled gluten-free. For certified gluten-free extracts, look for Nielsen-Massey brand at specialty-food markets and online at kingarthurflour.com.
Agave syrup or nectar is the naturally sweet juice extracted from the agave plant. It has a lower glycemic index and is lower in calories than table sugar, but is even sweeter. Use it in moderation when substituting for table sugar. Look for it near other sweeteners in large supermarkets and natural foods stores.
Pasteurized dried egg whites are a wise choice in recipes that call for uncooked egg whites. Look for brands like Just Whites in the baking or natural-foods section of most supermarkets. Reconstitute according to package directions or the recipe.
To improvise a double boiler, bring 2 inches of water to a simmer in a large saucepan; set a medium or large metal bowl over the simmering water. Allow at least an inch between the water and the bottom of the bowl.
174 calories; protein 4.1g; carbohydrates 29.6g; dietary fiber 1.4g; sugars 10g; fat 5.2g; saturated fat 2.5g; cholesterol 74.6mg; vitamin a iu 187.6IU; folate 9.4mcg; calcium 24mg; iron 0.9mg; magnesium 11.9mg; potassium 83.6mg; sodium 161mg; added sugar 22g.