Adapted recipe from Paula Wolfert’s The Cooking of Southwestern France
10 medium apricots, cut in half
In a bowl, toss the halved apricots with all of the sugar except for 1 tablespoon and set aside.
Meanwhile, in another bowl, whisk the 1/2 cup flour and salt. Whisk in the eggs. In a small saucepan, heat 1/2 cup of the milk with 3 tablespoons of the butter until the butter melts. Whisk the warm milk into the flour mixture just until smooth. Whisk in the remaining milk and cream. Add the Cognac and vanilla, cover and let rest at room temperature for at least 1 hour.
Preheat the oven to 220C (425F). Butter a 22 cm (9 1/2-inch) deep-dish pie plate or a well-seasoned iron skillet and dust with flour. Place the apricot halves in a single layer in the pie plate, adding any sugar from the bowl to apricots. Whisk the batter again and pour it over the apricots.
Bake the flognarde just above the center of the oven for 20 minutes, or until the top is just set and golden. Top with the remaining 1 tablespoon of granulated sugar and 1 tablespoon of butter. Bake for an additional 20 minutes, or until a knife inserted in the center comes out clean. Transfer to a rack to cool. Cut into wedges, and serve.