Molten Chocolate Cake 软心巧克力布丁蛋糕

Ingredients 材料:
100g butter (牛油)
100g dark chocolate  (黑巧克力)
1 tsp instant coffee powder (小匙即溶咖啡粉)
2 eggs (粒鸡蛋)
2 egg yolks (粒蛋黄)
50g caster sugar (幼糖)
50g plain flour (面粉)