Open apple pie with calvados - Le Coup de Grâce

Ingredients

• Seeds scraped from a vanilla pod
• Juice and zest from 1/2 lemon
• 1/4 cup calvados (or dark rum)
• 1/2 cup brown sugar
• 1/2 teaspoon ground cinnamon
• 4 big Gala apples, peeled and cored, cut in 3-4mm slices
• 450g flaky dough, thawed
• 1 egg + 1 teaspoon water, beaten
• 1/4 cup unsalted butter very cold, cut in mini cubes
• 3 tablespoons Double Fruits apricot jam