In a medium mixing bowl, beat 3/4 cup butter for 30 seconds. Add brown sugar and granulated sugar; beat until fluffy.
Add egg yolk and 1 teaspoon vanilla. Beat well. Beat in the flour to form stiff dough. Roll into 3/4 inch balls. Place balls on greased baking sheet.
Flatten balls with the bottom of glass dipped in sugar. Bake at 350°F for 9 to 11 minutes or until bottoms are golden brown. Remove to wire racks; cool cookies completely.
Frosting: In a saucepan cook and stir butter until lightly browned. Remove from heat; stir in powdered sugar until smooth. Gradually add whipping cream, stirring until smooth. Stir in vanilla. Frost cooled cookies and garnish with a pecan half or a sliced almond.