Pulse graham crackers in food processor until fine crumbs form. Mix in sugar and salt, then stir in melted butter until mixture resembles wet sand.

Press crumb mixture firmly into bottom of 9x13-inch pan lined with parchment paper. Freeze while preparing filling.

Beat cream cheese with hand mixer for 3-5 minutes until smooth and fluffy, scraping bowl often.

Add confectioners sugar and vanilla extract, beating until fully incorporated with no lumps.

In separate bowl, whip cold heavy cream until stiff peaks form.

Gently fold whipped cream into cream cheese mixture in three additions, being careful not to deflate.

Spread filling over chilled crust, smoothing top with offset spatula. Cover and refrigerate at least 6 hours or overnight.

Arrange blueberries in square at top left corner for flag field. Create alternating stripes with sliced strawberries and exposed white cheesecake.

Lift out using parchment overhang and cut into 20 bars with sharp knife, wiping between cuts.