For Sugar Cookie Bars

• Preheat the oven to 350 degrees and prepare an 8 inch square baking dish with parchment paper, leaving a parchment overhang to easily lift bars from pan after baking.
• In a large bowl, use an electric hand mixer to cream the butter and sugar until JUST combined – about 1 minute.
• Add egg, sour cream, and vanilla bean paste, mix to combine.
• Fold in the dry ingredients – flour, cornstarch, baking soda, and salt, until the dough comes together into a thick and slightly sticky ball.
• Use a small offset spatula to spread the dough into an even layer in the pan and bake for 16-17 minutes. The center will seem slightly under baked, but will finish setting up in the hot pan on the counter.
• Let bars cool completely, then frost and serve.

For the Strawberry Buttercream

• Puree about 1/2 C of fresh strawberries and set aside. Optional – run the puree through a fine mesh sieve to remove any larger chunks of berry and seeds. 
• In the bowl of your stand mixer or a large bowl with an electric hand mixer, cream the butter and cream cheese on medium high speed for 10 minutes. Be sure to scrape down the bottom and sides of the bowl as needed.
• Add 1 C of powdered sugar and mix on the lowest speed for 3 minutes. Then, repeat with the remaining 1 C of powdered sugar. 
• Add the strawberry puree and vanilla extract and mix to combine.
• Adjust the frosting consistency to your preference. Add a little extra powdered sugar if you like it thicker, or thin it out using a bit of heavy cream.
• Spread the frosting into an even layer on the cooled sugar cookie bars, top with sprinkles or freeze dried strawberries, slice, and serve.