Equivalent of 3 oreos inc base - 180 cals
Whipped cream, let’s say 40ml - 160 cals
Butter in the base - 70 cals
Cream cheese, full fat, 8tbs - 320 cals
Icing sugar in cream cheese filling 30g - 120 cals
Choc sauce - 50 cals
So round it up to around 900 cals give or take.
Hope you enjoyed it and don’t give yourself a hard time. Start again tomorrow and accept that there will be days you won’t always stick to your diet, losing weight can be hard and most people will have their bad days.