In a mixing bowl, combine the red velvet cake crumbs, softened cream cheese, powdered sugar, and vanilla extract. Mix well using an electric mixer or whisk until smooth and well blended.
Once the mixture is combined, use your hands to form small balls about 1 inch in diameter, placing them on a baking sheet lined with parchment paper.
Place the cake balls in the refrigerator for about 15 minutes to firm up.
While the truffles are chilling, melt the dark chocolate in a microwave-safe bowl, heating in 30-second intervals and stirring in between until smooth. If needed, mix in the vegetable oil to achieve a thinner consistency.
Remove the chilled truffles from the refrigerator. Dip each ball into the melted chocolate, ensuring they are completely coated, and return them to the parchment-lined baking sheet.
If desired, sprinkle red and white sprinkles on top of each truffle before the chocolate sets.
Allow the truffles to cool and set completely at room temperature or in the fridge for about 30 minutes.
Once set, the truffles are ready to serve. Enjoy your delicious red velvet truffles!