One slice of this tart will put you in the St. Patty's day mood! A crunchy chocolate cookie base holds a smooth Irish cream filling with just enough of a boozy kick to get the party started. A topping of pastel-green whipped cream and gold sugar pearls adds festive Irish-inspired flair!
For the crust: Preheat the oven to 350 degrees F. Rub the bottom of a 9-inch tart pan with a removeable bottom with shortening or butter and place a circle of parchment paper to cover the bottom. Lightly spray the tart pan with nonstick cooking spray.
Pulse the sandwich cookies in a food processor until fine crumbs form. You should have about 1 3/4 cups. Combine the cookie crumbs with the confectioners' sugar, melted butter and salt in a medium bowl (or pulse in the food processor) until combined. Transfer to the tart pan. Press the crumb mixture evenly up the sides of the pan to make about a 1/4-inch-thick crust, then press the remaining crumbs into the bottom. (Use a flat-bottomed glass to press the crust tightly along the bottom and sides.) Place on a sheet tray and bake for 12 minutes until the crust looks dry. (It may puff a bit—that is OK.) Set aside to cool completely.
For the filling: Whip the cream in the bowl of a stand mixer fitted with the whisk attachment to medium peaks. Transfer the whipped cream to a medium bowl and refrigerate.
Add the water to a small microwave-safe bowl and sprinkle the gelatin evenly over the top. Set aside to allow the gelatin to bloom and absorb the water.
In the same bowl used for the whipped cream, whip the cream cheese on medium speed until smooth, about 1 minute. Add the confectioners' sugar, Irish cream, vanilla and salt. Whip on low to combine. Scrape the bowl with a rubber spatula, then whip on medium speed until smooth, about 1 minute. Scrape the bowl and mix again if needed to smooth out the mixture.
Melt the gelatin in the microwave in 10 second intervals, swirling the bowl after each. It should take about 20 seconds until it is melted and clear. Spoon about 2 tablespoons of the cream cheese mixture into the hot gelatin and stir until smooth. Working quickly, pour the gelatin into the cream cheese mixture and blend on low to combine, then raise the speed to medium and mix until the mixture is slightly thickened, about 10 seconds.
Remove the whipped cream from the refrigerator and use a spatula to fold it into the cream cheese mixture in thirds. Pour the filling into the cooled tart shell, smooth the top and sprinkle the gold sugar pearls over the tart. Place in the refrigerator to chill for at least 8 hours and up to overnight. You can cover the tart by inverting a large bowl over top or by placing the tart pan in a 10-inch or larger cake pan and covering the cake pan with foil.
For the topping: Once the tart is completely chilled, put the softened cream cheese and confectioners' sugar in the bowl of a stand mixer and use a rubber spatula to mix until smooth. Add a couple drops of green gel food coloring and a splash of the heavy cream and mix with the spatula to loosen the mixture. Add the remaining heavy cream, Irish cream and vanilla. Secure the bowl to the stand mixer fitted with the whisk attachment. Whip on medium speed until medium-stiff peaks form, 1 to 2 minutes. Adjust the green color as desired.
Finish the tart. Unmold the tart by pushing the bottom of the tart pan up and out of the ring. Slide an offset spatula under the tart to loosen it from the removable bottom and parchment and transfer it to a serving platter. Put the whipped cream in a piping bag fitted with a large star tip (or simply cut a 1/2-inch opening at the base of the bag) and pipe swirls of whip cream along the edge of the tart. Sprinkle mini chocolate chips over the whipped cream. Serve immediately or store in the refrigerator up to 1 day.