Hailing from County Kerry, the famous producer of the brilliant yellow butter beloved by the global baking community, this Kerry apple slice is a celebration of both rich, golden butter and tender, juicy apples. Traditionally baked in a bastible, a cast-iron baking pot, over an open fire, we transformed this definitive baked good into another Irish classic: the traybake. So-called because they’re baked in a “tray” (a 13×9- or 9-inch square pan), these simple yet decadent desserts are a common source of comfort in the Irish home.
Apple Slice Traybake
- 1¼ cups (284 grams) unsalted butter, softened
- 1½ cups (300 grams) plus 1 tablespoon (12 grams) caster sugar, divided
- 4 large eggs (200 grams), room temperature
- 1½ teaspoons (9 grams) vanilla bean paste
- 3⅓ cups (417 grams) self-rising flour
- ½ teaspoon (1 gram) ground cinnamon
- ⅛ teaspoon ground allspice
- 4 cups (440 grams) ¼-inch-sliced Honeycrisp apples
- 1 tablespoon (15 grams) fresh lemon juice
- 2 tablespoons (24 grams) turbinado sugar
- Confectioners’ sugar, for dusting
- Vanilla Custard Sauce (recipe follows)
- Preheat oven to 350°F (180°C). Spray a light-colored 9-inch square baking pan with cooking spray; line pan with parchment paper, letting excess extend over sides of pan.
- In the bowl of a stand mixer fitted with the paddle attachment, beat butter and 1½ cups (300 grams) caster sugar at medium speed until well combined, about 2 minutes, stopping to scrape sides of bowl. Add eggs, one at a time, beating well after each addition. Beat in vanilla bean paste. (Mixture may look slightly curdled at this point, but batter will come together.)
- In a large bowl, whisk together flour, cinnamon, and allspice. With mixer on low speed, gradually add flour mixture to butter mixture, beating just until combined and stopping to scrape sides of bowl. Spread half of batter (about 596 grams) into prepared pan, smoothing into an even layer with the back of a spoon.
- In a large bowl, toss together apple slices, lemon juice, and remaining 1 tablespoon (12 grams) caster sugar. Arrange apple slices, flat side down, on top of batter. Top apple slices with remaining batter, spreading and swirling into an even layer with the back of a spoon. Sprinkle with turbinado sugar.
- Bake until a wooden pick inserted in center comes out clean and an instant-read thermometer inserted in center registers 200°F (93°C), 1 hour to 1 hour and 15 minutes, rotating pan and loosely covering with foil after 30 minutes of baking. Let cool in pan for 10 minutes. Using excess parchment as handles, remove from pan. Using a serrated knife, cut into pieces as desired. Dust with confectioners’ sugar, and serve warm with Vanilla Custard Sauce.
Vanilla Custard Sauce
- ⅓ cup (67 grams) caster sugar
- 3 large egg yolks (56 grams)
- ¼ teaspoon kosher salt
- 1½ cups (360 grams) whole milk
- 1 teaspoon (6 grams) vanilla bean paste
- Place a fine-mesh sieve over a medium metal bowl. Fill a large bowl with ice water.
- In another medium bowl, whisk together caster sugar, egg yolks, and salt.
- In a medium saucepan, heat milk over medium heat until steaming. (Do not boil.) Gradually whisk warm milk into sugar mixture. Return mixture to saucepan, and cook over medium heat, stirring constantly, until mixture is thickened, coats the back of a spoon, and holds a trail when a finger is dragged through, 10 to 20 minutes.
- Strain mixture through prepared sieve, and place in prepared ice bath; whisk until an instant-read thermometer registers 70°F (21°C). Stir in vanilla bean paste. Loosely cover and refrigerate until completely chilled, 3 to 4 hours.