Preheat oven to 350°F and two baking sheets with parchment paper.
Cream butter and granulated sugar on medium speed with a mixer until combined and fluffy. Add vanilla and egg; mix until just combined.
Add flour, baking powder, baking soda, and salt. Mix on low speed until just combined, and then medium speed until completely combined. The dough will be a little soft.
Scoop dough onto the the prepared baking sheets, arranging 2-inches apart.
Bake cookies for 6-8 minutes, or until crisp around the edges. Let cookies cool on pans for a few minutes before transferring to a cooling rack.
For the frosting:
Cream butter and shortening together on medium speed until smooth.
Scrape the sides of the bowl and add the almond extract.
Add half of the powdered sugar and mix on low speed until mostly combined, and then medium high speed until completely combined. Repeat with second half of powdered sugar and add the heavy cream, scraping the sides of the bowl as needed.
Remove about a cup of the frosting and stir in yellow food coloring.
Transfer white buttercream to a piping bag fitted with a small petal tip and the yellow buttercream to a piping bag fitted with a small circle tip.
Pipe petals first, with the larger end of the petal tip on the bottom and the narrow end up. Starting at the center of the cookie, moving out toward the edge, and then back toward the center, pipe petals around the cookie. Then pipe small yellow dots to fill in the center.