Line the bottom of a nine-inch springform pan with parchment paper.

In a food processor, pulse the biscuits to a fine crumb, then add the pistachios and salt and pulse a couple of times more until just combined. This allows the base to retain a crunchy texture— keep pulsing if you prefer a finer crumb. Transfer the mixture to a medium bowl.

Set a small heavy saucepan over medium heat. Add the butter and swirl to coat the bottom of the pan. After about two minutes, when the butter is just past melting, it will start to foam and then settle into a clear-ish golden liquid with brown specks (which are the milk solids browning and separating from the fat in the butter).

Pour the brown butter into the bowl with the biscuit mixture and use your hands or a spoon to combine until the mixture resembles wet sand and just holds together in your hand.

Spread the mixture over the bottom of the prepared pan, using the bottom of a glass or measuring cup to press it down into an even, smooth layer all the way to the pan’s edges. I usually allow a little bit of the mixture to creep up the sides of the pan by half an inch.

In a stand mixer fitted with the paddle attachment or in a large bowl with a handheld mixer, beat the cream cheese, sugar, and vanilla on medium speed until well combined, about two minutes. Scrape down the sides of the bowl with a flexible spatula, add the tahini, and beat again for one minute more.

In a medium bowl, whip the cream in a stand mixer fitted with the whisk attachment until soft peaks form, two to three minutes. Fold half of the whipped cream into the cream cheese mixture until just incorporated. Gently fold in the rest of the whipped cream until the mixture is combined.

Pour half of the filling over the biscuit base. Sprinkle the eight ounces halva and all but three tablespoons of the pistachios over the filling. Pour the remaining filling over the top and smooth the surface.

Cover the cake with plastic wrap and freeze for at least six hours or overnight.

At least 10 minutes before serving, remove the cake from the freezer to soften slightly. When ready to serve, loosen the cake by running a knife along the side of the pan, then remove the ring and place the cake on a serving dish. Scatter the remaining two to three tablespoons halva and three tablespoons pistachios over the cake.

To serve, dip a knife in boiling water, wipe it dry, and slice the cake, cleaning the knife between each cut.