How to Make It
In a large saucepan, combine the water, vinegar, sugar, garlic, jalapeños, bay leaves, crushed red pepper, salt, peppercorns and allspice berries and bring to a boil to dissolve the sugar. Add the shrimp and cook, stirring, for 1 minute. Transfer the shrimp and liquid to a large bowl and let cool to room temperature. Cover and refrigerate for 8 to 10 hours.
In a large saucepan, boil the cream over high heat until reduced by half, about 3 minutes. Add the spinach and cook, stirring, until wilted, about 1 minute. Transfer the spinach mixture to a bowl and let cool. Stir in the crème fraîche and lemon juice and season with salt.
Using a slotted spoon, lift the shrimp and jalapeños from the marinade and arrange on a platter. Garnish with cilantro leaves and serve the spinach dip in a bowl alongside.