In a mixing bowl, combine the softened butter and cream cheese. Use an electric mixer to beat them together until creamy and smooth.
Gradually add the granulated sugar and continue mixing until fully incorporated.
Slowly add the vanilla yogurt and vanilla extract to the mixture, blending until smooth and creamy.
In a separate bowl, whisk the all-purpose flour and pinch of salt together. Gradually incorporate the flour mixture into the wet ingredients until combined - be careful not to overmix.
Fold in the rainbow sprinkles until evenly distributed throughout the batter dip.
Transfer the dip to a serving bowl and chill in the refrigerator for at least 30 minutes to firm up before serving.
Serve with graham crackers, pretzels, or fresh fruit for dipping.
Notes
Garnish the dip with a few extra sprinkles on top for a festive look and serve with colorful dipping options arranged around the bowl.