iRaspberry Bombe

Prepare a 2-quart metal bowl or bombe mold by lining it neatly with plastic wrap, leaving overhang; chill the mold in the freezer.

Warm the dairy: In a medium saucepan, combine the whole milk, heavy cream, and vanilla bean (seeds and pod). Heat over medium until steaming around the edges, 5–7 minutes; remove from heat, cover, and steep 20 minutes.

Make the custard base: Whisk the egg yolks and 0.75 cup sugar in a bowl until slightly thickened, 1 minute. Rewarm the dairy to steaming, then slowly whisk about 1 cup into the yolks. Return the mixture to the saucepan and cook over medium-low, stirring constantly with a spatula, until the custard coats the back of the spoon and reaches 170–175°F, 6–8 minutes. Strain into a clean bowl, discard the vanilla pod, and chill until thoroughly cold, 3–4 hours.

Churn the vanilla ice cream: Churn the cold custard in an ice cream maker until it reaches soft-serve consistency, 20–25 minutes. Immediately spread most of the soft ice cream in an even 0.75-inch layer up the sides and across the bottom of the chilled mold, reserving enough to cap the bombe later (about 1.5 cups). Freeze until the shell is firm, 45–60 minutes.

Make syrup for sorbet: In a small saucepan, bring the water and 1 cup sugar to a simmer over medium heat, stirring to dissolve, 3–4 minutes. Cool to room temperature, then chill until cold, about 30 minutes.

Prepare raspberry base: Blend the raspberries with the chilled syrup and lemon juice until completely smooth, 30–60 seconds. Strain through a fine sieve to remove seeds; chill the puree until very cold, 1–2 hours.

Churn the sorbet: Churn the cold raspberry base in an ice cream maker until softly spoonable, 15–20 minutes. Spoon the sorbet into the vanilla-lined mold, filling the cavity and leaving about 0.5 inch at the top for the cap; smooth the surface. Freeze until beginning to firm, 45–60 minutes.

Cap and freeze: Spread the reserved vanilla ice cream over the top to seal the bombe. Cover with plastic wrap and freeze until solid all the way through, 6–8 hours or overnight.

Unmold and serve: Peel back the top plastic, invert the mold onto a chilled serving plate, and briefly wrap the exterior of the bowl with a warm, damp towel or dip the bowl in warm water for 5–10 seconds to release. Lift off the mold and remove the plastic. Slice with a knife warmed in hot water and wiped dry; serve immediately.