Making homemade white chocolate is incredibly simple. All you have to do is melt the ingredients together over low heat and whisk until mixed.
It is important to use very low heat and not overcook the mixture as it will burn quickly. Turn off the heat and let it cool for about half a minute before pouring into the molds.
While the white chocolate is hardening in the fridge, melt the dark chocolate. You'll want to choose high-quality dark chocolate, ideally with more than 80 to 85% chocolate. That will balance out the white chocolate.
My favorite is Theo's 85% dark chocolate bars.
Melt in a double-broiler or in the microwave in short 20 second intervals, making sure to stir constantly or between each microwave interval. You want to stir the chocolate to spread out the heat and use the already melted chocolate to melt the rest of it.
Be careful not to overcook the chocolate. The best way to get the perfect chocolate consistency and temperature is to use the warm chocolate to melt the remaining unmelted chunks by stirring it. In other words, don't heat the chocolate to the point where the chocolate is fully melted or bubbling.
Remove the molds with hardened white chocolate from the fridge. Pour the melted dark chocolate on top to the level you want the finished chocolate, about 1/3 of an inch thick. Then place the molds with both types of chocolate in the fridge to harden for about 20 minutes.
Remove the chocolate from the molds, serve, and enjoy!