Preheat your oven to 350°F (175°C).
In a large bowl, whisk together flour, baking soda, and salt.
In another bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
Add in eggs one at a time, followed by the vanilla extract, mixing well after each addition.
Gradually mix the dry ingredients into the wet ingredients until just combined.
Spread the cookie dough into a greased 9x13 inch baking pan, smoothing the top.
Bake in the preheated oven for 20 to 25 minutes, or until the edges are lightly golden and a toothpick comes out clean.
Allow the cake to cool in the pan for about 10 minutes, then transfer it to a wire rack to cool completely.
Once cool, spread the pink buttercream frosting evenly over the top.
Top with sprinkles, slice, and serve!