Sift flour, salt, cornstarch into a medium bowl. Give it a whisk.
In a standing mixer fitted with a paddle attachment, cream the butter and sugar together until fluffy.
Scrape down the bowl before adding eggs.
Add eggs. Mix until combined.
Add dry ingredients to the wet.
Mix on low with a paddle attachment until just combined. Drizzle in vanilla and mix.
Transfer dough to parchment paper.
Roll into a disk.
Chill for about 1 hour.
Press to flatten and roll between 2 pieces of parchment paper.
Roll dough to ½ inch.
Use a 2.5 inch circle cookie cutter.
Place cookies onto a baking sheet with a silpat.
Bake for 12 min.
Let the cookies cool before decorating.
For the Buttercream:
In a standing mixer fitted with a paddle attachment, cream the room temperature butter. Add confectioners sugar and mix. Add cream and vanilla.
Separate buttercream into 2 bowls. Dye green and pink.
Transfer the pink to a piping bag fitted with a 101 tip. Transfer the green to a bag fitted with a leaf tip.
For the Roses:
Cut small sheets of parchment paper. Add some buttercream to a piping nail to attach the paper. Pipe a cone.
Create the rose by making small arcs with the tip, which gradually increase in size as you get toward the edge of the flower. The piping tip should be sharp side facing up.
Transfer roses to cookie using toothpicks. Pipe the leaves with a leaf tip.
Video
Notes
For these cookies I used a 101 tip, which looks like a small curved tear drop. This tip lets you create a more closed bud-like flower and it's also great for piping small flowers.