Ingredients

Makes 1 serving

　　

For cake

1/3 cup walnuts (1 ounce)

　　1 1/2 tablespoons sugar

　　2 tablespoons unsalted butter, cut into small pieces

　　1/2 teaspoon finely grated fresh lemon zest

　　1 large egg

　　2 tablespoons all-purpose flour

　　

For syrup

1 lemon

　　3 tablespoons sugar

　　2 tablespoons water

　　2 teaspoons mild honey

　　Accompaniment: whole-milk yogurt (preferably Greek)

　　

Special Equipment

a 6- to 8-ounce gratin dish or ramekin

　　

Make cake:

Step 1

Put oven rack in middle position and preheat oven to 350°F.

　　

Step 2

Pulse nuts in a food processor until coarsely chopped and reserve 1 1/2 tablespoons in a small bowl. Add sugar and a pinch of salt to nuts in processor and pulse until nuts are finely chopped. Add butter and zest and process until smooth, then add egg and process until blended, scraping down side of bowl. Add flour and pulse just until incorporated, 2 or 3 times (do not overblend). Pour batter into ungreased dish and sprinkle with reserved nuts.

　　

Step 3

Bake until cake is browned around edge and puffed, and a wooden pick or skewer inserted in center comes out clean, 20 to 25 minutes. Transfer cake in dish to a rack.

　　

Make syrup while cake bakes:

Step 4

Finely grate 1/4 teaspoon zest from lemon, then halve lemon and squeeze enough juice to measure 2 teaspoons.

　　

Step 5

Bring lemon juice, sugar, water, and honey to a boil in a very small saucepan, stirring until sugar is dissolved, then boil 1 minute. Stir in zest and cool to warm.

　　

Step 6

Run a thin knife around edge of cake to loosen and pour 3 tablespoons syrup over hot cake in dish, letting syrup run down sides and underneath cake. Cool cake at least 15 minutes. Transfer to a plate and serve with remaining syrup and yogurt.