This walnut slice is exactly what holiday baking should be: a moist, buttery ground-walnut cake topped with a crisp, glossy yellow egg yolk glaze. If you grew up with walnut bars on the Christmas tray, the flavor will feel familiar.
It is a good bake for Christmas, Easter or a Sunday coffee table, and it goes quickly once the glaze has set. The cake is a single sheet pan, so cutting 30 neat squares is the only fussy part. Have your ground walnuts ready before you start.
At a Glance
- Prep time: 20 min
- Baking time: 25 min (plus cooling until the glaze is dry)
- Servings: 30 slices (12×16-inch / 30×40 cm sheet pan)
- Difficulty: Medium
- Calories: about 210 kcal per slice
- Trend: Retro classic
Ingredients
(US cups, with metric in brackets)
For the cake
- 1 cup plus 2 tablespoons (250 g) softened butter
- 1 1/4 cups (150 g) powdered sugar
- 2 1/2 cups (250 g) ground walnuts
- 1 1/4 cups (150 g) all-purpose flour
- 1 1/4 teaspoons (1/2 packet, about 6 g) baking powder
- 6 egg whites (from medium eggs)
- 1 pinch salt
For the egg yolk glaze
- 6 egg yolks
- 2 to 2 1/3 cups (250 to 300 g) powdered sugar, sifted
- 1 teaspoon vanilla extract (or 1 packet / 8 g vanilla sugar)
Instructions
- Whip the egg whites: Beat the egg whites with the pinch of salt to stiff, firm peaks. Set aside.
- Cream the butter: In a large bowl, beat the softened butter with the 150 g powdered sugar until fluffy. Give it at least 5 minutes; it should be pale and airy.
- Mix the dry ingredients: In a separate bowl, stir together the flour, baking powder and ground walnuts.
- Make the batter: Alternately fold the dry mixture and the whipped egg whites into the butter mixture, gently by hand (or on the lowest speed). Work carefully so the batter stays light.
- Bake: Spread the batter evenly on a 12×16-inch (30×40 cm) sheet pan lined with parchment paper. Bake in an oven preheated to 350°F (180°C) for about 20 to 25 minutes, until the edges pull away from the pan and a toothpick comes out dry.
- Make the glaze while it bakes: Stir the egg yolks with the sifted powdered sugar and the vanilla until you have a thick, glossy, smooth glaze. Stir patiently and do not whip it into foam, because you do not want bubbles.
- Glaze the hot cake: Immediately after taking the cake out of the oven, pour the glaze over the piping-hot cake and quickly spread it over the whole surface with an offset spatula. The heat of the cake sets the glaze.
- Dry and cut: Let the cake cool at room temperature until the glaze is completely dry and no longer sticky to the touch. Only then cut it into squares.
Video Recipe
Tips for Perfect Walnut Slice
- Clean cuts. To keep the glaze from cracking, cut with a thin, sharp knife. Dip it in hot water and wipe it dry before every cut.
- Storage. The slices taste best the next day, when the flavors have melded. Keep them cool in a tin or covered with foil; they stay soft for up to a week.
- Pasteurized yolks. The glaze is made with raw egg yolks and only sets from the heat of the cake. If you want extra safety, use pasteurized egg yolks or pasteurized liquid yolks.
Easy Variations
- Coffee note. Add 1 teaspoon of very finely ground coffee beans to the walnut batter. It brings out the flavor of the nuts.
- Lemon glaze. If the yolk glaze is too sweet for you, stir 1 tablespoon of lemon juice into it. The glaze will be lighter and fresher.
Frequently Asked Questions (FAQ)
- Is the raw egg yolk glaze safe? The hot cake partly cooks and dries the glaze, but the surface may not reach the 160°F (71°C) that food-safety guidelines recommend for eggs. To be on the safe side, use pasteurized egg yolks, and keep the slices cool.
- Why does the glaze crack or fall off after drying? Usually the glaze went onto a cake that had already cooled, or it was too thick and dry. It needs to meet the hot surface of the cake so that it bonds to it.
- How long do walnut bars keep? Stored cool in a tin or covered with foil, they stay soft for up to a week. The glaze needs the heat of the freshly baked cake to set, so this recipe is best made fresh rather than frozen.
- Can I make them ahead for Christmas? Yes. They taste best a day after baking, so bake them 1 to 2 days before serving and keep them in a tin.
- What can I use instead of walnuts? Ground hazelnuts or pecans work in the same amount, with a slightly different flavor.
Let the baked cake dry well and serve it cut into neat rectangles with good coffee. It also suits a Christmas cookie tray.
The recipe is based on a version by LiViera Desserts, adapted by the We Cook With Love team.
Enjoy! Try more recipes from our kitchen.
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