Preheat the oven to 350° F and spray 2 9” baking pans with baking spray or line with parchment paper.
In a large mixing bowl, cream the butter and sugar with a hand mixer on medium speed for 1 minute until fluffy and pale yellow in color.
Add in the eggs one at a time, stopping the mixer before each addition. You may have to scrape down the sides-stop the mixer.
In a medium size bowl combine the flour, baking powder, baking soda and salt. In a large mixing cup or a small bowl, combine the yogurt, milk, and vanilla extract.
Alternate adding the flour and yogurt mixture to the bowl, starting and ending with the flour. Use 1/3rd of the flour for each addition.
Pour the batter evenly into the two baking pans and bake for 30-35 minutes until the edges of the cake are golden brown and break away from the pan- or when the top of the cake feels firm and not jiggly.
Cream the butter and confectioners sugar on medium speed until fluffy in a large bowl with the hand mixer. Add in the vanilla extract and milk and cream again on medium speed for about 1 minute.
In a small bowl take out 1/2 cup of frosting and add 1/4 cup of sprinkles to it and mix.