Combine butter, powdered sugar, and extracts in a large bowl using an electric mixer until completely mixed and fluffy.Note: make sure that the butter is room temperature, not chilled at all.
Add flour. Mix thoroughly.
Add milk and mix. The dough might look crumbly, but it will come together just fine.
Scrape the bowl with a rubber spatula and press the dough together.
Fit a sturdy pastry bag (if using a disposable bag you can double it up for strength) with a large star frosting tip. Add a few spoonfuls of cookie dough. Note: I prefer to fill the bag only about halfway. It takes less pressure to pipe the cookies vs. a loaded bag of cookie dough. Refill the bag as needed.
Pipe cookies into a rosette shape on an ungreased baking sheet (or silpat lined baking sheet). Space cookies 2" apart.
Bake cookies for 15 minutes. Edges should be slightly golden.Allow cookies to cool for 5 minutes then remove from baking sheets and place onto a wire cooling rack.
Video
Notes
Store cookies in an airtight container for up to 10 days. Cookies freeze well and can be stored in the freezer for up to 2 months.Tips
Use LARGE frosting tips (at least 1/2" wide).
The dough is thicker than frosting so you'll need to use more pressure to pipe the shapes.
The cookies will flatten slightly when baked, as all cookies do. You can chill the cookies before baking for 30 minutes if you'd like to prevent some of the spreading. I've never done this. I like the look of the slightly flattened swirls.
Cookies are best eaten cold so let them cool completely to allow them to crisp up.