Pear Chocolate and Hazelnut Upside Down Cake

STEP 1: SET THE OVEN LOW AND PREPARE THE PAN

Heat the oven to 325°F (165°C), conventional — not 350°F, and not convection. A lower oven over a longer time sets the crumb without driving the moisture out of it. Cut a parchment circle for the base of a 9-inch (23 cm) solid-bottomed cake pan, butter the sides, and set the pan on a rimmed baking sheet. Do not use a springform pan; molten caramel finds every seam.

STEP 2: TOAST AND GRIND THE HAZELNUTS

Spread the blanched hazelnuts on a tray and toast for 8–10 minutes, until they smell nutty and are just blond — they should not darken. Cool them completely, then pulse in a food processor with 2 tablespoons taken from the measured flour until they reach the texture of coarse cornmeal. The flour absorbs the oil the nuts release and stops them going to paste. Stop while there is still a little grit; a bit of texture is welcome.

STEP 3: BUILD THE CARAMEL

Melt the butter in a small heavy saucepan, add the light brown sugar and the pinch of fine sea salt, and stir over medium heat for 2–3 minutes, just until the sugar has dissolved and the mixture is smooth and glossy. Do not take it to a dark caramel: it sits on the base of the cake for another 45 minutes in the oven, so it needs to start pale or it will bake to bitterness. Pour it into the lined pan and tilt to cover the base evenly.

STEP 4: SLICE AND LAY THE PEARS

Peel, halve and core the pears, saving every trimming and any juice for the glaze. Cut each half lengthwise into slices a full 1/4 inch (6 mm) thick, toss them with the lemon juice, and fan them over the caramel in overlapping circles, working from the outside in. Pack them close, so the layer reads as solid pear with no caramel showing through. Do not poach the pears first: poaching leaches pear flavor into liquid that is then thrown away, and it is the most common reason a pear cake tastes of nothing. The raw slices cook in the caramel under the batter and their juice stays in the pan.

STEP 5: MIX THE BATTER

Whisk the ground hazelnuts, remaining flour, cocoa powder, baking powder, baking soda and salt together and set aside. Beat the softened butter with both sugars on medium-high for a full 4–5 minutes, until genuinely pale and aerated. Add the eggs one at a time, beating well after each, then the vanilla extract. Beat in the cooled melted chocolate. On low speed, add the dry mixture in three additions alternating with the buttermilk in two, beginning and ending with the dry. Stop the moment the last streak disappears — overmixing develops gluten and gives a tight crumb that reads as dry even when the cake is correctly baked.

STEP 6: FILL AND BAKE BY TEMPERATURE

Spoon the batter over the pears in dollops and spread it gently level so the fruit is not disturbed. Bake for 40–50 minutes, starting to check at 38 minutes. The cake is done when an instant-read thermometer pushed into the center of the sponge — into cake, not into a pear — reads 205–208°F (96–98°C), and no higher. A skewer cannot tell a cake at 205°F from one at 215°F, and those ten degrees are the whole difference between a moist crumb and a dry one. If your oven dial is unreliable, the thermometer removes the problem entirely.

STEP 7: REDUCE THE PEAR GLAZE

While the cake bakes, simmer the reserved pear trimmings and juices with the pear juice and granulated sugar for 12–15 minutes. Strain hard, pressing the solids, then return the liquid to the pan and reduce it to about 3 tablespoons of loose syrup. Stir in the pear brandy, if using. Everything the fruit gave up during preparation is concentrated here and goes back onto the cake.

STEP 8: REST BRIEFLY, THEN TURN OUT

Cool the cake in its pan on a wire rack for exactly 8–10 minutes. Any less and it is too fragile to move; any more and the caramel sets and welds the pears to the pan. Run a thin knife around the edge, set the serving plate over the pan, and invert in one confident movement. Lift the pan away and peel off the parchment. Anything that sticks can be lifted with a small offset spatula and pressed back into place — the glaze will hide the join.

STEP 9: GLAZE THE WARM CAKE

Brush the reduced pear syrup over the warm turned-out cake, covering the fruit and any joins. Work while the cake is still warm so the glaze sinks in and sets to a light shine rather than sitting on the surface.

STEP 10: OPTIONAL — SPIKED HAZELNUT DECORATION

Press a toothpick or fine skewer into the base of each toasted whole hazelnut. Boil the granulated sugar and water without stirring to a light amber caramel, take the pan off the heat, and dip each nut so a tail of caramel forms. Suspend them point-down over the edge of a counter, weighted, with parchment underneath, until the tails set into spikes. Trim the tails and set the nuts on the cake just before serving; they soften within an hour in humid conditions, so make them last.

STEP 11: SERVE

Serve the cake slightly warm or at room temperature, in generous wedges, with creme fraiche or lightly whipped unsweetened cream. Do not serve it fridge-cold — chilling mutes pear before it mutes anything else on the plate.