1cup(227g)salted butter, softened to room temperature
¾cup(164g)neutral flavored oil, like canola, vegetable, grapeseed, etc
1 ¼cups(265g)granulated sugar
¾cup(86g)powdered sugar
½teaspoonbaking soda
½teaspooncream of tartar or baking powder (see note)
½teaspoonsalt
1heaping tablespoonfresh lime zest
2tablespoonssour cream
2large eggs
1teaspoonvanilla extract
5 ½cups(781g)all-purpose flour
Granulated sugar for pressing the cookies
Frosting:
¾cup(170g)salted butter, softened
2tablespoonssour cream
1teaspoonfresh lime zest
½teaspooncoconut extract (add another 1/2 teaspoon for a stronger coconut flavor)
¼teaspoonvanilla extract
6cups(684g)powdered sugar
1 to 2tablespoonsfresh lime juice
1 to 2tablespoonsmilk, if needed
Garnish (optional):
Small fresh lime wedges (see note)
Toasted coconut
Instructions
Preheat the oven to 350 degrees F (or 325 degrees F for convection bake) and line several half sheet pans with parchment paper.
For the cookies, in the bowl of a stand mixer fitted with the paddle attachment or in a bowl using a handheld electric mixer, add the butter, oil, granulated sugar and powdered sugar.
Sprinkle the baking soda, cream of tartar, and salt across the top of the sugars (don't add the baking soda and cream of tartar in one lump or it might clump while mixing). Mix until well-combined and super creamy, 1-2 minutes, scraping down the sides of the bowl as needed.
Add the lime zest and mix until combined.
Add the sour cream, eggs and vanilla, and mix until well-combined, 1 to 2 minutes, again scraping down the sides of the bowl as needed.
Add the flour and mix until no dry streaks remain and the mixture is evenly combined. Don't over mix.
Scoop the dough into about 3-tablespoon sized portions (I use a #20 cookie scoop) and roll into balls. Place several inches apart on the prepared baking sheets.
Add 1/3 to 1/2 cup granulated sugar to a shallow dish or bowl. Lightly spray the bottom of a flat-bottomed glass with cooking spray and dip the bottom of the glass into the sugar.
Press each cookie into an even thickness; the edges will ruffle out a bit, but take care not to press too thin. I press the cookies between 1/4 and 1/2-inch thick. Dip the bottom of the glass into the sugar between each press.
Bake the cookies for 7 to 9 minutes until the edges are set (it's ok and preferable if the center of the cookies looks slightly under baked).
Let the cookies cool for a few minutes on the baking sheets before removing to a cooling rack to cool completely.
For the frosting, in a medium bowl (can use a handheld or stand mixer) combine the butter, sour cream, lime zest, coconut extract, and vanilla extract.
Mix until thick and smooth and creamy.
Add the powdered sugar and mix until mostly combined. Add the lime juice, and mix until well-combined and the frosting is smooth and creamy.
If you want the frosting a bit thinner/easier to spread, add milk, a tablespoon at a time to adjust the consistency.
Frost the cooled cookies.
For the garnish, if desired sprinkle the top of each cookie with a bit of toasted coconut and a fresh lime wedge. (Pat the lime wedges lightly with a paper towel before garnishing the cookies.)
Notes
Cream of Tartar or Baking Powder: Either can be used in the cookie dough (don't use both). The cream of tartar gives a slightly tart flavor to the dough (similar to the flavor in a snickerdoodle cookie that calls for cream of tartar). I prefer using baking powder for a more neutral flavor, but either works great, and the cream of tartar is a bit more of a classic flavor with these soda shop-style sugar cookies.Make-Ahead: These cookies do amazingly well baked, frosted, sprinkled and frozen. Wait until they are thawed to add the toasted coconut and fresh lime wedge. To freeze: place the frosted cookies in a single layer on a baking tray. Freeze and then put them into a tupperware container or ziploc bag (and separate layers with pieces of parchment or wax paper). They thaw great and taste amazing.