Pecan Shortbread Cookies with Maple Glaze

3 1/4 cups all-purpose flour
1/2 cup rice flour
1/2 teaspoon baking powder
1/2 teaspoon salt
1 pound butter
1 1/2 cups confectioners' sugar
2 teaspoons vanilla extract
1 1/2 cups chopped pecans

Icing:
1/2 cup butter
2 cups confectioners' sugar
1 teaspoon vanilla extract
2 teaspoons hot water
2 teaspoons maple flavoring

Mix together the flour, rice flour, baking powder and salt in medium size bowl. Set aside.

In a mixer with the paddle attachment, cream butter on low speed for 3 to 4 minutes. Add sugar and vanilla extract and continue to cream on moderately low speed for 2 minutes. On low speed mix in the dry ingredients, blending just until the particles of flour are absorbed. Add in the pecans. Roll into logs about 2 inches in diameter. Wrap in plastic or parchment, and refrigerate or freeze until needed. (These can also be rolled out and cut into shapes.)

Slice the logs and bake at 325 degrees F for about 40 minutes.

Icing: Mix the butter, confectioners' sugar and vanilla extract together. Add in the water and maple flavoring to reach the consistency for pouring or spreading icing.