Need help caramelising white chocolate in the oven

[xafirefly]

hello to everyone in here! i need your help. i’m trying to caramelise white chocolate using the oven method (baking for 10 mins - taking out of the oven to spread chocolate evenly - then back to the oven to reach golden color) but the chocolate just becomes crumbly and grainy. this is my second time doing it and failing i’ve followed every instruction i read on the internet and have watched. the white chocolate i’m using also has a high cocoa butter content (32%). we don’t have a microwave at home so i have no choice but opt for the oven method. i hope you all can help me. thank you so much!