Cream together well the butter, sugar and vanilla extract well.

Beat in the eggs, one at a time, beating well after each addition.

Sift together the flour, salt and baking powder and fold in until a soft dough forms.

Chill the dough for an hour or two to make it easier to roll out on a floured board to about 1/4 inch thick. Cut out cookies with 2 1/2 inch cookie cutter. Bake on a parchment lined cookie sheet at 375 degrees for about 10 minutes or until the cookies start to brown at the edges. Cool on a wire rack.

Beat together the egg whites, cream of tatar and icing sugar to firm peaks.

You may need to add another couple of tablespoons of icing sugar to make sure the frosting is stiff but able to be piped onto the cookies.

Remove about 1/3 of the frosting and put it in a piping bag with a #3 or #4 tip or in a Ziploc bag with the corner shipped off. Pipe a circle around the top of each of the cookies.

Add the color paste to the remaining frosting, for these cookies we used Wilton Cornflower Blue color paste.

Beat in a teaspoon of cold water at a time to thin the frosting down just to a point were the frosting falls to a smooth surface when the whisk or electric beaters are removed. Don't over thin the icing, use only enough water as it takes to get the frosting to that point and only a teaspoon at a time.

The thinned colored frosting can then be placed in a piping bag with a #3 or #4 tip or in a Ziploc bag with the corner shipped off and piped into the middle of the circles on the cookies just until the surface is covered.

Let the cookies dry for a half hour or so before piping on the white frosting to complete your design of snowflakes, trees , stars or whatever your imagination creates.

Let the cookies dry overnight before storing them in an airtight container.