So I tested this several times with different types of sugar and to be honest I could not tell which one was which. I used granulated sugar, super fine caster sugar, and powdered sugar and they all dissolved and were smooth.  The only thing I recommend is weighing the sugar so you’re using the proper amount. I like using 50-60 grams of sugar for two cups of cream, so ¼ cup of granulated sugar is 50 grams and ½ cup of powdered sugar is about 60 grams. If you use just ¼ cup of powdered sugar (30 grams), it will still be good but it’ll be more like a sweetened whipped cream and you’ll miss that “fully body” texture I was talking about earlier.