8 ounces (2 sticks) butter, room temperature
2 cups cake flour (you can use all purpose but cake flour makes a much softer cookie)
3/4 cup confectioners' sugar
1/2 teaspoon baking powder
1/2 teaspoon vanilla extract
Combine all ingredients; use hands to knead until ingredients are blended. Press dough into ungreased pans. Before baking, mark rectangle cookie lines with knife to get the authentic Panera shortbread cookie look!
Bake at 325 degrees F for about 20 minutes, or until lightly browned. Don't over bake!
Watch out, these are melt in your mouth addictingly ( a word I just made up) good!
Note: If you like a sweeter shortbread cookie try the frosting recipe below, very similiar to paneras shortbread cookie frosting recipe:
1 1/2 cups powdered sugar
1 stick unsalted or salted butter depending on your taste ( I prefer salted) softened
2 Tbsp Milk ( Whole, Skim, 2%) any will work just fine.
2 tsp Vanilla Extract
Whip for 30 seconds on low, then crank it up to high speed for 1 1/2 to 2 minutes.
Add food coloring and spread over cookies!