On the stovetop, fill a medium sized sauce pan with 1-2" of water and bring it to a low simmer. Place a double broiler pan or otherwise heat-proof bowl on top of the sauce pan. The bowl should not be touching the water.
Add the 10 ounces chopped white chocolate and heavy cream to the bowl, stirring constantly with a whisk until the chocolate has melted. It will be thick and almost seem like it has "broken", but this is what you want! Remove from heat.
Add the champagne and whisk again to completely combine and the mixture is smooth.
Transfer to a separate medium bowl and cover with plastic wrap - place in the fridge to set (at least 1 hour, preferably 2). If you find that your mixture is too soft to scoop into balls, melt another 1 ounce of white chocolate and stir it into the bowl until smooth again, and refrigerate for another 1 hour (minimum).
Line a baking sheet with parchment paper, wax paper or a nonstick silicon mat. Set aside.
Use a small cookie scoop or teaspoon (depending on the size you'd like them to be) to scoop each ball onto prepared baking sheets. Note that the mixture will be softer than your typical chocolate truffle ganache, but should still be scoopable and not runny.
Use your hands to quickly roll each into a ball, place back on baking sheet and place back in the fridge to set again since they're on the softer side to begin with and you've now warmed them up with your hands a little (at least 30 minutes in the fridge, or 15 minutes in the freezer).
In a double boiler, melt white chocolate candy melts until smooth and using a toothpick or candy dipper, coat each ball in chocolate and place back on prepared baking sheet. If you're going to add any sprinkles or other garnish, top each one as soon as you've placed them back on the sheet.
Let the chocolate set, serve and enjoy! If making them ahead of time, store in an airtight container in the fridge until ready to serve.