End your Valentine's Day dinner on a sweet note with a decadent molten chocolate lava cake. In a microwave-safe bowl, melt dark chocolate and butter together. In a separate bowl, whisk eggs, sugar, and vanilla extract. Gradually add the melted chocolate mixture and flour, stirring until well combined. Pour the batter into greased ramekins and bake in a preheated oven until the edges are set but the center is still gooey. Serve the warm cakes with a dusting of powdered sugar and a scoop of vanilla ice cream.