Cream butter by hand or with a mixer fitted with the paddle attachment until light and fluffy. Add icing sugar and cream until smooth. Add egg yolks slowly to butter mixture and blend until smooth. Stir in vanilla and almond extract. Add pastry flour and salt and combine until dough comes together. Shape into a disc, wrap and chill for at least 2 hours before rolling.
Preheat oven to 325 F. On a lightly floured surface, knead dough slightly to soften (this will prevent cracking as it is rolled. Roll out dough to ¼ -inch thick and cut out desired shapes. Unused dough can be re-rolled and cut again (just chill for a few minutes if it becomes too soft). Place cut-outs on a greased or parchment-lined baking sheet and bake on the center rack of the oven for 10 to 12 minutes, until bottom of cookies turn a light golden brown. Remove cookies from pan onto a cooling rack and cool completely.
For the icing
Stir together all ingredients to blend, then beat with electric beaters on high speed until mixture is stiff, about 7 minutes. Tint portions of icing as desired.
To store, keep icing tightly covered, with plastic wrap resting directly on surface of icing.
To decorate cookies
Tools: Small disposable piping bags, Variety of piping tips, including a small 1/8-inch plain tip, Decorator sugars
To create a satiny finished cookie thin the icing a little by adding water, a few droplets at a time, until desired consistency is achieved. First pipe an outline of icing around edge of cookie with 1/8-inch plain tip. Using a brush, fill in cookie with icing to coat (it’s just like colouring inside the lines).
For a colourful swirl effect, add drops of a contrasting colour on the cookie and swirl in with a toothpick.
For a textured contrast, let royal icing dry completely, then pipe on top. Sprinkle with decorator’s sugar, if desired. Have fun and play!!!