Peanut Butter-Banana Semifredo
- Prepare the crust: Spray 9x5 metal loaf pan with cooking spray and line with plastic wrap, leaving 2 inch overhang on all sides; spray the plastic wrap. Finely grind the peanuts and graham crackers in food processor. Add melted butter and pulse til combined. Press mixture into bottom of prepared pan and refrigerate.
- Make ice cream: Bring 2 inches water to a simmer in a saucepan over med heat. Fill a bowl with ice water. Whisk yolks, 1/2 c sugar, banana puree, liqueur and salt in large metal bowl. Place the bowl over the pot of simmering water. (Make sure that the bowl doesn't touch the water) Whisk til thickened, 8-10 minute Place bowl of thickened mixture into bowl of ice water to cool.
- Beat heavy cream and remaining 1/4 c sugar with mixer til cream just holds stiff peaks. Gently fold into banana custard. Heat the peanut butter in the microwave til soft, about 20 seconds and let cool slightly. Drop spoonfuls of peanut butter into banana cream and fold a few time to swirl.
- Spread mixture over crust. Cover with plastic wrap and freeze til firm; 9 hours. Lift out of pan using plastic wrap and cut into 1 inch slices.