feat: add Butter Swirl Shortbread Cookies. Fixes #449.

cook/cookies-and-bars/Butter Swirl Shortbread Cookies.cook

@@ -0,0 +1,17 @@
+>> source: https://www.fifteenspatulas.com/butter-swirl-shortbread-cookies/
+>> serves: 24 cookies
+>> total time: 25 minutes
+
+Preheat the oven to 350°F.
+
+Place the @unsalted butter{1%cup}, @confectioners' sugar{114%g} and @vanilla{1%tsp} in a #large bowl{}, and beat with an #electric mixer{} until combined, light, and fluffy.
+
+Add the @all-purpose flour{240%g} and @salt{1/2%tsp} and mix until it’s crumbly and looks like it can’t be mixed more.
+
+Add the @whole milk{1%Tbsp} and keep mixing. The dough should clump together after about ~{15%seconds}.
+
+Place the dough into a #pastry bag{} fitted with a very #large star tip{}, and pipe onto a silicone mat lined #baking sheet{}, with no more than 12 cookies per sheet.
+
+Bake the cookies for ~{15%minutes} or until lightly golden.
+
+Let them cool completely (on the tray is fine), and enjoy!

docs/cookies-and-bars/butter-swirl-shortbread-cookies.md

@@ -0,0 +1,66 @@
+---
+comments: true
+tags:
+  - cookie
+  - dessert
+---
+# :cookie: Butter Swirl Shortbread Cookies
+
+![Butter Swirl Shortbread Cookies](../assets/images/butter-swirl-shortbread-cookies.jpg)
+
+| :fork_and_knife_with_plate: Serves | :timer_clock: Total Time |
+|:----------------------------------:|:-----------------------: |
+| 24 cookies | 30 minutes |
+
+## :salt: Ingredients
+
+- :butter: 1 cup unsalted butter
+- :candy: 114 g confectioners' sugar
+- :icecream: 1 tsp vanilla
+- :ear_of_rice: 240 g all-purpose flour
+- :salt: 0.5 tsp salt
+- :glass_of_milk: 1 Tbsp whole milk
+
+## :cooking: Cookware
+
+- 1 large bowl
+- 1 electric mixer
+- 1 pastry bag
+- 1 large star tip
+- 1 baking sheet
+
+## :pencil: Instructions
+
+### Step 1
+
+Preheat the oven to 350°F.
+
+### Step 2
+
+Place the unsalted butter, confectioners' sugar and vanilla in a large bowl, and beat with an electric mixer until
+combined, light, and fluffy.
+
+### Step 3
+
+Add the all-purpose flour and salt and mix until it’s crumbly and looks like it can’t be mixed more.
+
+### Step 4
+
+Add the whole milk and keep mixing. The dough should clump together after about 15 seconds.
+
+### Step 5
+
+Place the dough into a pastry bag fitted with a very large star tip, and pipe onto a silicone mat lined baking sheet,
+with no more than 12 cookies per sheet.
+
+### Step 6
+
+Bake the cookies for 15 minutes or until lightly golden.
+
+### Step 7
+
+Let them cool completely (on the tray is fine), and enjoy!
+
+## :link: Source
+
+- <https://www.fifteenspatulas.com/butter-swirl-shortbread-cookies/>

mkdocs.yml

@@ -124,6 +124,7 @@ nav:
       - Brown Butter Iced Oatmeal Cookies: cookies-and-bars/brown-butter-iced-oatmeal-cookies.md
       - Brown Butter Macadamia Nut: cookies-and-bars/brown-butter-macadamia-nut.md
       - Browned Butter Blondies: cookies-and-bars/browned-butter-blondies.md
+      - Butter Swirl Shortbread Cookies: cookies-and-bars/butter-swirl-shortbread-cookies.md
       - Buttery Shortbread: cookies-and-bars/buttery-shortbread.md
       - Chewy Brownies: cookies-and-bars/chewy-brownies.md
       - Chewy Peanut Butter Cookies: cookies-and-bars/chewy-peanut-butter-cookies.md