In a large bowl, use an electric mixer to cream together butter and cream cheese until smooth and well-combined.

 Stir in eggs and vanilla extract.

In a separate bowl, whisk together flour, sugar, baking powder, and salt.

With electric mixer on  low-speed, gradually stir dry ingredients into butter/cream cheese mixture until  completely combined.

Cover bowl with plastic wrap and place in refrigerator to chill for 30 minutes.

Once dough has chilled, scoop  1 ½ Tablespoon-sized balls and roll between your palms until smooth. Roll through powdered sugar and then place on prepared baking sheet, 2" apart. 

Bake on 350F (175C) in center rack for 10-12 minutes.  Allow cookies to cool completely on baking sheet before enjoying.