MAKE THE HOMEMADE AMARETTI BISCUITS:
Preheat oven to 325°F. Line two baking sheets with parchment paper.
In a bowl whisk together almond flour and granulated sugar.
In a separate clean bowl beat egg whites with salt until soft peaks form.
Gently fold almond flour mixture into egg whites. Add almond and vanilla extracts folding until just combined. Mixture will be thick and sticky.
Using a small cookie scoop or spoon form walnut-sized balls. Roll each ball in powdered sugar to coat completely.
Place on prepared baking sheets spacing 2 inches apart they will spread and crack.
Bake 15-18 minutes until lightly golden with characteristic cracks on surface. Let cool completely on baking sheets.
Yasmin's dedication to homemade biscuits adds authentic Italian flavor and impressive technique.

MAKE THE AMARETTI CRUST:
Preheat oven to 350°F. Wrap outside of 9-inch springform pan tightly with aluminum foil to prevent water bath leakage.
In a food processor pulse cooled amaretti biscuits into fine crumbs. You should have about 2 cups of crumbs.
In a bowl mix amaretti crumbs melted butter sugar and salt until mixture resembles wet sand.
Press mixture firmly and evenly into bottom of prepared pan using the bottom of a measuring cup to compact.
Bake crust 10 minutes until lightly golden. Remove and let cool while preparing filling. Reduce oven temperature to 325°F.

MAKE THE AMARETTO CHEESECAKE FILLING:
In a large bowl or stand mixer beat cream cheese on medium speed until completely smooth and fluffy about 3 minutes. Scrape down bowl frequently.
Add sugar and flour beating until fully incorporated and smooth about 2 minutes.
Add eggs one at a time beating on low speed after each addition just until combined.
DO NOT overbeat after adding eggs this incorporates too much air and can cause cracking.
Add sour cream amaretto liqueur almond extract vanilla extract and lemon zest if using. Mix on low speed until just combined and smooth. Scrape down bowl and stir by hand to ensure no lumps remain.
Pour filling over cooled crust smoothing top with offset spatula.

BAKE THE CHEESECAKE:
Place springform pan in large roasting pan. Carefully pour hot water into roasting pan until it reaches halfway up sides of springform pan.
WATER BATH IS CRUCIAL for even baking and preventing cracks.
Bake 55-65 minutes until edges are set but center still jiggles slightly when gently shaken about 3-inch diameter in center. Internal temperature should reach 150°F.
Turn off oven and crack door open slightly. Let cheesecake cool in oven for 1 hour.
GRADUAL COOLING PREVENTS CRACKING.
Remove from oven and water bath. Remove foil. Run a thin knife around edge of cheesecake to loosen. Let cool completely at room temperature about 2 hours.

OPTIONAL SOUR CREAM TOPPING:
While cheesecake cools mix sour cream sugar and amaretto until smooth. Spread over cooled cheesecake. Return to 350°F oven for 10 minutes. Cool completely.

CHILL AND SERVE:
Cover cheesecake and refrigerate at least 4 hours or overnight.
CHILLING IS ESSENTIAL for proper texture and clean slicing.
Before serving run a hot knife around edge and remove springform ring.
Garnish with toasted sliced almonds and crushed amaretti biscuits if desired.
Slice with a hot clean knife wiping between cuts for clean slices.