In a medium mixing bowl, stir together flour, salt, and baking soda. Set aside.
With an electric mixer, cream butter and sugar together. Mix in eggs and vanilla. Add dry ingredients to wet and beat, starting on low speed, until a dough is formed. Mix in sprinkles
Form the dough into a ball, cut in half, Wrap in Saran Wrap and chill in the refrigerator for 1 to 2 hours.
Preheat oven to 350 degrees F. Place parchment paper on two baking sheets.
Remove dough from refrigerator and roll out, a portion at a tome, to 1/8 inch thick. Cut out shapes Using a cookie cutter of choice. Repeat with remaining dough
Place cookies on baking sheets and bake 10 to 12 minutes, until edges are lightly browned.
Wait 5 minutes and then place cookies on cooling rack. Cool completely before dipping in icing.
While cookies cool, make icing by creaming together all ingredients. If icing is too thick, add milk in small amounts at a time. If too thin, add additional icing sugar. Stir in food coloring (if desired) and sprinkles.
Place icing into a bowl and serve with cookies on the side.