3 bars, about 12 ounces, good quality white chocolate - I use Green & Blacks because I adore the vanilla flecks
Preheat oven to 250
Break up white chocolate bars in a large glass dish, or on a baking sheet. You can use parchment here, but it is kind of a pain when you're stirring and it's not necessary.
Place chocolate in oven for 15 minutes.
Remove from oven, and with a rubber spatula, stir chocolate and spread into a thin, even layer before returning to oven.
Repeat this process until your chocolate has turned a light golden-tan color. It took mine about 2 hours, but all ovens are different, so just judge by the color.
There will be points during this process when you're stirring and the chocolate gets clumpy and you think you've ruined everything. You haven't. Just keep stirring and smoothing the chocolate and it will all come together.
After about 2 hours, you will have a golden puddle of caramelized white chocolate.
Remove tray from oven and stir for about 3-5 minutes.
Transfer chocolate to wax paper or parchment. Smooth into an even layer, as thick or thin as you'd like, and allow to cool until hardened. I left mine overnight.
Break into pieces and store in an airtight container.