Toss the sliced strawberries with 2 tablespoons granulated sugar in a large bowl. Let sit at room temperature for 20 minutes until juicy and slightly softened. This helps them soften the graham crackers as the cake sets.

In a large bowl with an electric mixer, beat the cold heavy cream, powdered sugar, and vanilla on medium-high speed until stiff peaks form, about 3 to 4 minutes. The cream should hold its shape when you lift the beaters. Do not overbeat or it will become grainy.

Spread a thin layer of whipped cream on the bottom of a 9x13 inch dish. Arrange a single layer of graham crackers over the cream, breaking pieces as needed to fill gaps. Spread one-third of the remaining whipped cream over the crackers, then top with half the macerated strawberries and their juices.

Add another layer of graham crackers, pressing down gently. Spread half the remaining whipped cream, then the rest of the macerated strawberries. Top with a final layer of graham crackers and the last of the whipped cream, spreading it smoothly to the edges.

Cover tightly with plastic wrap and refrigerate for at least 8 hours or overnight. The graham crackers will absorb moisture and soften into cake-like layers. Garnish with fresh halved strawberries just before serving.