Line a baking sheet with parchment paper to prevent sticking.
Beat softened butter in a medium bowl for 2-3 minutes until pale and creamy.
Add powdered sugar and continue mixing for 2 more minutes until light and fluffy.
Mix in vanilla extract thoroughly.
Add all-purpose flour and cornstarch to the butter mixture and combine just until dough forms.
Place dough in a piping bag fitted with a large open star tip.
If dough is too stiff, add 1-2 teaspoons heavy cream to achieve proper piping texture.
Pipe desired shapes onto the prepared baking sheet.
Chill piped cookies in the refrigerator for 30 minutes while preheating oven to 350°F (175°C).
Bake cookies for 8-10 minutes until edges are lightly golden but tops remain pale.
Allow cookies to cool completely on a rack.
If desired, melt chocolate or almond bark in microwave-safe bowl in 20-second intervals, stirring until smooth.
Dip cooled cookies halfway into melted chocolate and place on parchment-lined tray.
Decorate with candied sprinkles before chocolate sets.
Allow dipped cookies to firm up before serving.