Pour your cold heavy cream into a large, chilled bowl. Using a hand mixer on medium-high speed, begin beating the cream. After about one minute, add the powdered sugar and vanilla extract. Continue beating until medium peaks form—meaning the cream holds its shape but the peaks gently fold over when you lift the beaters. This takes approximately four to five minutes total. Be careful not to overbeat, as the cream can quickly turn grainy.

Spread a thin layer of whipped cream across the bottom of a 9-by-13-inch pan. This prevents the cookies from sticking. Arrange vanilla wafers in a single layer, covering the entire bottom. You may need to break a few cookies to fill gaps. Spread a generous, thick layer of whipped cream over the cookies, using about one-third of your remaining cream. Arrange a layer of sliced strawberries over the cream, slightly overlapping them for complete coverage.

Continue building your lasagna by repeating the layering process two more times: cookies, thick whipped cream, strawberries. You should end with strawberries as your top layer. Take a few extra cookies and crush them into coarse crumbs using your hands or a sealed bag with a rolling pin. Sprinkle these crumbs over the top strawberry layer for added texture and visual interest.

Cover your dish tightly with plastic wrap and refrigerate for at least three hours, though overnight is even better. This resting period allows the cookies to absorb moisture from the cream and strawberries, softening into tender layers that slice beautifully. Just before serving, dust the top lightly with additional powdered sugar through a fine-mesh sieve.