Cheesecake-Filled Cinnamon Coffee Cake

Instructions

1. 1

   Allow about 60 minutes for the butter and cream cheese to soften at room temperature. Bring the eggs and buttermilk out at the same time. The butter should yield easily to gentle pressure but must not be melted. Keep these ingredients out for no more than 2 hours before baking.

2. 2

   Heat the oven to 175°C conventional / 350°F, or 155°C fan / 310°F. Line the base and sides of a 23 × 33 cm metal baking tin, at least 5 cm deep (9 × 13 × 2 inches), with baking parchment, leaving overhang on the two long sides. No greasing is needed.

3. 3

   Make the cinnamon crumbs: combine 150 g of the flour, all 140 g brown sugar, all 12 g cinnamon and 1 g of the salt in a bowl. Add 100 g of the softened butter and work it in with a fork until there are moist crumbs and small, irregular clumps. Set aside.

4. 4

   Make the cheesecake filling: using an electric hand mixer on low speed, beat the cream cheese with 90 g of the granulated sugar until smooth. Beat in 1 egg and 5 ml of the vanilla just until combined, scraping down the bowl. Avoid whipping in lots of air.

5. 5

   In another bowl, whisk together the remaining 300 g flour, the baking powder, baking soda and remaining 2 g salt.

6. 6

   In a large bowl, beat the remaining 170 g butter and 180 g granulated sugar with the electric mixer for 3–4 minutes, until noticeably paler and fluffy. Beat in the remaining 3 eggs one at a time, scraping the bowl between additions, then mix in the remaining 10 ml vanilla.

7. 7

   On low speed, add the flour mixture in three additions, alternating with the buttermilk in two additions, beginning and ending with flour. Stop as soon as the batter is combined, then fold briefly with a spatula to catch any flour at the bottom. The batter should be thick and spreadable. Do not taste the raw batter or filling because they contain uncooked flour or eggs.

8. 8

   Spread about three-fifths of the cake batter, approximately 640 g, evenly in the prepared tin. Spoon all the cheesecake filling over it and gently spread it into an even layer, stopping about 1 cm short of the edges. Dot the remaining cake batter, approximately 420 g, across the filling and carefully join the dollops with a spatula; a few small gaps are fine. Scatter all the cinnamon crumbs evenly over the surface.

9. 9

   Bake on the middle shelf for approximately 65 minutes, checking from 60 minutes; it may need up to 70 minutes. The crumbs should be golden, the cake edges should feel set, and the centre should have only a slight, set wobble rather than a liquid ripple. A skewer inserted into a cake section should show moist crumbs but no wet batter. Check that the cheesecake filling at the centre reaches at least 71°C/160°F with an instant-read thermometer. If the top browns too quickly, loosely cover it with foil for the remaining baking time.

10. 10

    Place the tin on a wire rack and cool for 90 minutes. Refrigerate the cake in its tin within 2 hours of leaving the oven. Chill for at least 4 hours, until completely cold and the cheesecake layer is firm; cover once the cake is cold.

11. 11

    Lift the chilled cake onto a cutting board using the parchment. Stir the icing sugar and milk together until smooth and thickly pourable, then drizzle all the icing over the top. Cut into a 4-by-4 grid to make 16 slices. Allow about 10 minutes for this glazing and cutting stage; the drizzle can be served without a separate setting period.