Ingredients

• 1 kg firm eating applesBraeburn, Cox or Pink Lady; Bramley is bred to fall apart and will flood this
• 30 g unsalted butterfor the filling
• 45 g soft light brown sugarfor the filling
• 1 tsp ground cinnamon
• 1 tbsp lemon juice
• 120 g plain flour
• 70 g rolled oatsrolled, not instant
• 90 g soft light brown sugarfor the crumble
• 110 g unsalted butterfor the crumble, to be browned
• 1/4 tsp fine sea salt

For the custard

• 400 ml whole milk
• 150 ml double cream
• 5 egg yolkslarge
• 45 g caster sugar
• 75 ml pure maple syrupa dark amber grade; pale syrup vanishes into 550 ml of dairy
• 1/4 tsp fine sea saltfor the custard

Method

1. 01

   Heat the oven and cook the apples

   Heat the oven to 190C fan / 210C conventional. Melt the butter in a wide 28 cm frying pan over medium-high heat, add the apple chunks, brown sugar, cinnamon and lemon juice, and cook for 5-7 minutes, turning every couple of minutes. You are looking for glossy pieces with a little colour on their edges that still hold a sharp corner when pressed. Not soft. A wide pan matters: crowd 800 g of apple into a saucepan and it steams into sauce before it ever caramelises.

   30 g unsalted butter · 45 g soft light brown sugar · 1 tsp ground cinnamon · 1 tbsp lemon juice

   For a sharper fillingSwap 200 g of the eating apples for Bramley: enough to sauce the gaps without flooding it.

2. 02

   Fill the dish

   Tip the apples and every drop of pan syrup into a 1.5 litre baking dish, roughly 20 x 28 cm, and spread them level. Leave 2 cm of headroom below the rim. The juices rise and bubble hard in the last ten minutes, and a full dish will spill onto the oven floor. Sit the dish on a baking tray to be safe.

3. 03

   Brown the butter

   Put the butter in a small pale-coloured pan over medium heat. It melts, foams, then falls quiet as the water boils off; keep swirling and watch the milk solids on the base. At 4-5 minutes they will turn hazelnut brown and the smell shifts from buttery to nutty and almost toffee-like. Pour it immediately into a mixing bowl, scraping in the brown sediment. That sediment is the flavour. Leave 5 minutes to cool to just warm.

   110 g unsalted butter

4. 04

   Make the crumble

   Add the flour, oats, brown sugar and a pinch of salt to the cooled brown butter. Stir with a fork, then squeeze handfuls together and let them crumble apart between your fingers. You want a mixture of clusters, from pea to hazelnut size, with loose sandy crumbs in between. If it is uniformly sandy, the butter was still too hot: chill the bowl 10 minutes and squeeze again.

   120 g plain flour · 70 g rolled oats · 90 g soft light brown sugar

5. 05

   Top and bake

   Scatter the crumble loosely over the apples, mounding it slightly and taking it right to the edges of the dish so no fruit is exposed. Do not press it down. A compacted topping steams into a lid instead of crisping. Bake for 30-35 minutes until the surface is deeply golden brown all over, not just at the edges, and thick apple syrup bubbles slowly up the sides. Rest 15 minutes before serving.

6. 06

   Start the custard

   While the crumble bakes, pour the milk and cream into a heavy saucepan and bring to just below a simmer over medium heat. Small bubbles at the edge, steam rising, no rolling boil. Meanwhile whisk the egg yolks with the caster sugar in a bowl for about a minute, until pale and slightly thickened. Whisking well here dissolves the sugar; left as loose grains it can scramble the yolks on contact with hot dairy.

   400 ml whole milk · 150 ml double cream · 5 egg yolks · 45 g soft light brown sugar

7. 07

   Temper and thicken

   Pour a ladleful of the hot dairy into the yolks while whisking continuously, then a second, then tip the warmed yolks back into the pan. Set over low heat and stir constantly with a spatula, scraping the base and corners in a figure of eight, for 6-10 minutes. It is ready at 82-84C on a probe, or when it coats the back of a spoon thickly enough that a finger drawn through leaves a clean channel that does not flood back. Above 85C the yolks curdle, so pull it the moment it thickens.

8. 08

   Reduce the maple and finish

   In a small pan, boil the maple syrup hard for 90 seconds to 2 minutes until it has reduced by about a quarter and smells noticeably darker and more caramelised. Whisk it into the finished custard along with the sea salt, then pour the whole lot through a fine sieve into a warm jug. This catches any strands of cooked egg and is what separates a good custard from a silky one. Serve warm and generously poured, with the crumble still hot.

   75 ml pure maple syrup · 1/4 tsp fine sea salt