Preheat your oven to 375 degrees F.
In a medium sized bowl, combine the flour, baking powder and salt. Set aside.
In a large mixing bowl, cream together the butter and sugar for about 3 minutes until light and fluffy.
Add in the egg, sour cream, lemon juice, zest and vanilla. Mix until combined.
Slowly add in your flour mixture while stirring until everything is incorporated. Add in the fresh raspberries and mix once more.
Press the batter into a greased 9x13 dish (or a bakers quarter sheet like I used) and spread it out evenly with your hands or a rubber spatula.
Bake your sugar cookie bars for 15-17 minutes or until the edges have just started to turn golden.
Allow cookie bars to cool completely.
Mix all your ingredients together for your frosting until creamy. Add more powdered sugar or milk if needed for the texture.
Spread your frosting evenly over your cooled cookie bars. Cut into squares and serve with additional raspberries on top.