In a large bowl, combine butter, sugar, cookie butter and vanilla until mixed well. Your butter will need to be soft but not melted for this to work.
When dough is well mixed it will be slightly tacky but not too sticky. If it is still very sticky to the touch, add more powdered sugar, a teaspoon at a time.
When the dough is ready, roll into small balls about 1" large.
Place on wax paper and chill in fridge or freezer for at least 1 hour.
When truffles are ready, melt chocolate 35 seconds at a time in microwave, stirring in between each time in until fully melted.
Add 1 tsp vegetable oil and mix. If chocolate is slightly runny (comes off a spoon in ribbon, not in clumps), it is ready. If it is still too thick, add more oil slowly (a drizzle at a time- you dont want too much.)
Using a truffle fork (or toothpick), dip balls into chocolate and remove to set on wax paper.
When all balls are coated, set in a cool, dry place to set. I like to keep them in the fridge and pop them out a few minutes before eating so they are slightly cool.
Keeps up to one week in an airtight container in the refrigerator.