Preheat oven to 400 degrees F. Butter the bottom and sides of 3 ramekins (I used 220 ml ramekins). Then dust the ramekins with some confectioners' sugar.
Place the eggs, confectioner's sugar, salt, vanilla extract and instant coffee into a large bowl. Mix them with a electric mixer for about 2 minutes.
Break the chocolate into pieces (if you don't use the chocolate chips). Place the butter and chocolate in a small microwave-safe bowl.
Microwave on high for 1 to 2 minutes, or until smooth; stopping to stir every 25 seconds (or use a double boiler to melt the chocolate). Let cool slightly.
Add the chocolate mixture into the egg mixture. Whisk to combine.
Then add the flour, and whisk just until combined (do not over mix).
Pour the batter into prepared ramekins (do not overfill).
Place the ramekins on a baking sheet. Bake on the middle rack of the oven for 11-13 minutes or until edges are set but center is still soft; don't overbake. Remove from the oven and let sit for 2 minutes.
Run a small knife around the edges to loosen and invert onto dessert plates or you can serve each molten lava cake still in the cup.