Instructions for Cookie
Preheat oven to 350 degrees. Prepare a 9-inch spring form pan by spraying the bottom and sides with non-stick spray.
Combine the butter and sugar in a medium bowl and mix until smooth. Add in the egg, vanilla, baking soda, salt and cream of tartar. Mix until well combined. Slowly add in the flour and mix until fully incorporated. Fold in the white chocolate chips.
Pour the batter into your prepared spring form pan and press to the edges. Top with a few more white chocolate chips for presentation.
Bake for 20-22 minutes, just until edges are a golden brown color. Remove from the oven and allow cooling for 15 minutes. Then, remove the spring form side and allow the cake to cool completely before frosting.
Instructions for Frosting
With a stand mixer or a hand mixer, combine the butter and powdered sugar. Add in the salt, vanilla and heavy cream. Mix everything until it’s smooth and creamy. Scoop into a piping bag with a 1m tip and decorate your cake. Top with sprinkles before the icing sets.