Preheat the oven to 350 degrees. Line 2 baking sheets with parchment and set aside.
Whip the soft butter in the mixer using the paddle attachment.
Slowly stir in the flour, confectioner’s sugar, cornstarch and vanilla until the dough pulls together.
Use a 4 tsp cookie scoop to scoop the dough onto the prepared baking sheets.
Press a fork gently into the tops of the cookies.
Add sprinkles – if desired.
Bake for 14 minutes. Remove and allow to cool completely before decorating with chocolate.
To decorate, melt the chocolate in a microwave-safe bowl according to package directions.
Dip each cookie halfway into the chocolate, place back on the parchment lined sheet and immediately add sprinkles before the chocolate solidifies again.
Store in an airtight container at room temperature.