Toffee Coffee Cake Surprise
Author: 
Yield: 1 Bundt cake • 12 to 16 servings
 
Ingredients
For the Toffee (30 ounces/850 g, approximately 4 cups)
  • 1 cup (150 g) whole almonds, darkly toasted (see page 19)
  • 8 ounces (2 sticks/225 g) unsalted butter, plus more for the pan
  • ½ cup plus 2 tablespoons (125 g) granulated sugar
  • ½ cup plus 2 tablespoons (140 g) firmly packed dark brown sugar
  • 3 tablespoons corn syrup
  • 1 teaspoon pure vanilla extract
  • ½ teaspoon kosher salt
  • 8 ounces (225 g) good quality dark chocolate (60 to 72% cacao), coarsely chopped
For the Toffee Coffee Cake
  • 6 ounces (1 ½ sticks/170 g) unsalted butter, cool but not cold, cubed
  • 2 cups (255 g) all-purpose flour
  • 1 cup (130 g) cake flour
  • 1½ cups (330 g) firmly packed dark brown sugar
  • ¾ cup (150 g) granulated sugar
  • 1 tablespoon pure vanilla extract
  • ¾ teaspoon kosher salt
  • 4 ounces (115 g) homemade toffee (see above), or 3 Skor or Heath bars, chopped very finely (see Baked Note)
  • ½ cup (75 g) coarsely chopped toasted almonds (see page 19)
  • 2 teaspoons baking powder
  • ¼ teaspoon baking soda
  • 1 large egg
  • 2 large egg yolks
  • 1½ cups (345 g) sour cream
  • 3 tablespoons confectioners’ sugar, for dusting
Instructions
Make the Toffee
  1. Butter a 9-by-13-by-2-inch (23-by-33-by-5-cm) glass or metal baking pan (do not use nonstick spray).
  2. In the bowl of a food processor, pulse the almonds until they are super finely chopped, almost but not quite powdery. Place in a bowl and set aside.
  3. Place the butter in a medium pan over low heat. When the butter is halfway melted, add the granulated and brown sugars, the corn syrup, and 2 tablespoons water. Cook over low heat, stirring very gently with a silicone or rubber spatula, until completely combined. Stop stirring. Clip a candy thermometer onto the side of the pan and turn the heat up to medium-high. The mixture will start to bubble and turn brown. If the browning seems uneven, gently swirl the pan during the cooking process, but do not stir. After 10 to 15 minutes, when the mixture is just under 300°F (150°C), remove the pan from the heat and remove the candy thermometer. Stir in the vanilla and salt. Pour into the prepared pan. After the mixture has evened out, wait 1 minute, then sprinkle the chocolate pieces all over the toffee. Wait for the chocolate to melt, about 3 minutes, then use an offset spatula to spread the chocolate into an even layer. Sprinkle the ground almonds over the chocolate in an even layer and ever so gently press them into the chocolate. Freeze the pan for about 30 minutes.
  4. Remove the pan from the freezer and break the toffee into pieces with a sharp knife. Measure out 4 ounces (115 g), chop it very finely, and set aside; save the remainder of the toffee for another use. Store for up to 1 week between layers of parchment in an airtight container at cool room temperature.
Make the Toffee Coffee Cake
  1. Preheat the oven to 350°F (175°C). Generously spray the inside of a 10- or 12-cup (2.4- or 2.8-L) Bundt pan with nonstick cooking spray; alternatively, butter it thoroughly, dust it with flour, and knock out excess flour.
  2. In the bowl of a standing mixer fitted with the paddle attachment, beat the butter, both flours, the brown and granulated sugars, the vanilla, and salt on medium speed until the mixture resembles sandy crumbs, 2 to 3 minutes.
  3. Scoop out 2⁄3 cup (90 g) of this crumb mixture and place it in a large bowl. Stir in the reserved ounces (115 g) toffee and the almonds and set aside.
  4. Sprinkle the baking powder and baking soda over the remaining crumb mixture in the mixing bowl. Beat on medium speed for 15 seconds to incorporate. Add the egg and egg yolks and beat on medium speed until combined. Scrape down the sides and bottom of the bowl. Add the sour cream and beat until smooth. Scrape down the sides and bottom of the bowl and beat again for seconds.
  5. Spoon half the batter into the prepared pan. Smooth the surface with an offset spatula. Spoon the dry toffee/nut mixture on top of the batter in an even layer, keeping it in the center of the batter, away from the sides of the pan. (If some of the toffee mixture touches the sides, nudge it gently back toward the center as best you can.) Cover with the remaining batter and smooth the top with an offset spatula.
  6. Bake, rotating the pan halfway through the baking time, until a toothpick inserted in the center comes out clean, 45 to 55 minutes, depending on your Bundt pan size or shape. Transfer the pan to a wire rack to cool for about 30 minutes. Use a small knife or very small spatula to loosen the sides of the cake from the pan. Turn the cake out onto the rack and let it cool completely. Sift confectioners’ sugar over the cake and serve.
Notes
How to store: the cake can be stored, tightly covered, at room temperature for up to 3 days.
Recipe by Baked Sunday Mornings at http://bakedsundaymornings.com/2015/01/22/oven-toffee-coffee-cake-surprise/