This is by far the best molten lava cake recipe made with a splash of Kahlua.
Preheat oven to 425F.
Grease 6 custard cups with oil.
Melt chocolate and butter in a small pot on low heat. Remove from heat. Add in flour and sugar and stir to its well incorporated. Mix in eggs, vanilla and Kahlua.
Pour batter into prepared custard cups, and bake for 14 minutes, or until edges are firm.
Run a knife around edge to loosen and turn out onto serving plate. Serve warm.