4. Transfer to the prepared baking pan and spread in an even layer. Bake until set, 23 to 25 minutes. Cool completely in the pan.

Make the buttercream:

1. Place the butter and cream cheese in a stand mixer fitted with the paddle attachment. (Alternatively, use an electric hand mixer and large bowl.) Beat on medium speed until smooth, about 2 minutes. Beat in the crème de menthe, peppermint extract and salt.

2. With the mixer on low speed, gradually add in the sugar. Once incorporated, increase the speed to medium-low and mix until smooth and fluffy.

3. Spread in an even layer over the brownies. Refrigerate at least 30 minutes. Meanwhile, make the ganache.

Make the ganache:

1. Place the chocolate in a medium heatproof bowl. Heat the cream in a small saucepan over low heat until bubbling round the edges, then pour it over the chocolate mixture.

2. Let sit for about 10 minutes, then stir with a spatula until completely smooth. Let it cool at room temperature for about 10 minutes, then use it as soon as it starts to thicken up.

3. Remove the brownies from the refrigerator and spread the ganache in an even layer over the buttercream with an offset spatula or knife. Refrigerate for at least 30 minutes before slicing and

Recipe notes: The brownies can be baked a day in advance, covered, and stored at room temperature. Store in a covered container in the refrigerator for up to four days.

Creme de menthe alternative: To make the brownies without creme de menthe, use 2 teaspoons peppermint extract and green food coloring.

(Kelli Foster is associate food editor for TheKitchn.com, a nationally known blog for people who love food and home cooking. Submit any comments or questions to editorial@thekitchn.com.)