Line a 9x13 baking dish with parchment paper. Set aside.
Preheat oven to 375 degrees.
In a large bowl using an electric mixer combine butter and sugar until light and fluffy.
Add eggs and vanilla and beat until combined.
Next add in flour baking soda and salt until a dough forms.
Spread cookie dough into the prepared pan.
Bake 12-15 minutes until puffed and golden brown.
Allow cookie bars to cool completely in pan.
Make the butter cream frosting.
In a large bowl with an electric mixer whip your butter.
Add in the powdered sugar and whip again.
Add in the milk and vanilla and beat again until light and fluffy.
Spread frosting all over the cookie bars.
Sprinkle with holiday sprinkles or holiday chips.
Slice into bars and serve.
Notes
Store these in an airtight container for up to 3 days or in the fridge for 5 days.
You can add peppermint or almond flavor to the frosting if you like.
I use these mini holiday chips I find around the holidays but sprinkles work just as well.
You can add chocolate chips or white chocolate chips to the dough if you like.
These are rich but you can cut the bars as large or small as you like.