Beat egg whites until they form soft peaks, then add sugar gradually, followed by vanilla extract.

In a food processor, pulse the saltine crackers into a fine powder. Add the baking powder and chopped pecans, and pulse until the pecans are finely ground. (Alternatively, you can place the saltine crackers in a zip lock bag and use a rolling pin to crush them. Then, chop the pecans by hand. Mix the crackers, baking powder and chopped pecans together in a small bowl).

Fold in the saltine cracker mix into the egg white mixture, then pour the combined mixture into a a greased pie pan (9" diameter) or a 12"x12" pan. (You can also double the recipe and make it in a 9" x 13" pan or a 13" round pie plate. I like this pie plate from Ikea.)

Bake the crust at 350 degrees Fahrenheit for 30 minutes. Unless you over-stirred, the crust will puff up and then settle down as it cools (similar to a meringue). Cool completely.

While the crust is baking, pour the heavy whipping cream into a stand mixer with the whisk attachment. Start slowly and then build up to high speed and whisk the heavy cream until it whips up. Be careful not to churn it into butter. Add ⅔ cup of powdered sugar and the additional ½ teaspoon of vanilla extract to the whipped cream, just before it is completely whipped.

Layer the sliced fresh strawberries on top of the crust and then cover the strawberries with a layer of whipping cream. Garnish with additional strawberries. You can serve the dessert right away or chilled.