Lemon Grass-Pistachio Semi Freddo with Mango Caramel Sauce

4 cups heavy cream
1/4 cup confectioners' sugar
2 tbsp lemon grass molasses
15-20 lemon cookies
1/2 cup pistachios

Lemon Grass Molasses:
1/2 cup sugar
Juice of 1 lemon
4 stalks lemon grass, chopped

Mango Caramel Sauce:
1 cup sugar
1/2 cup water
1/2 stick butter
1/2 tsp kosher salt
2 mangoes, chopped

Start the molasses: in a heavy bottom saucepan, add sugar and lemon juice. Cook until sugar is dissolved and add the lemon grass. Bring to a boil and cook, stirring occasionally, for about 8 minutes.

Begin by whipping cream with confectioners' sugar until you get soft peaks. Add lemon grass molasses and stir 2 times gently to combine and just streak the molasses through the cream.

Take a large plastic bag and using a wooden rolling pin, smash the lemon cookies into rough pieces. In a mini chopper, add pistachios. Pulse to get a rough chop and add to cookies. To assemble, take a ramekin and add a layer of cookies and pistachios first, followed by cream, cookies and pistachios, and finally cream again. Use an off-set spatula or the back of a knife to flatten the tops. Set in the freezer for 45 to 60 minutes to freeze. Run a knife around the edges when set and invert onto a plate.

Make the mango caramel sauce by adding sugar, water and mangoes to a small saucepan and set over medium-high heat. Once the sugar has dissolved and the caramel reaches a dark amber stage, add butter and salt and swirl to combine. Remove from heat and drizzle over semi-freddo cookies and cream.