Mix first four ingredients with a pastry blender until crumbly.
Pat into a 9x13 pan. (It doesn't need to go all the way to the edges. You will be crumbling this up.).
Bake at 350 for 15-20 minutes.
After this has cooled, crush it into fine crumbs. Reserve one third of the crumbs for topping, and spread the remaining crumbs evenly in the bottom of the pan.
Whip the cream and set it aside.
Combine remaining ingredients in a large mixer bowl and beat at high speed until very stiff.
Combine strawberry mixture with whipped cream.
Pour filling into crust and top with reserved crumbs, lightly pressing the crumbs into the filling.
Cover and freeze until firm.
I always make double the crust amount because I end up munching it as I go. (How can you miss with butter, brown sugar and nuts, especially pecans?) If you do this you may want to bake your crust in a larger pan.
Regarding the egg whites - I used only one the last time I made this, and in my Kitchenaid it went all the way to the top of my bowl. It turned out great, but if you prefer a lighter filling, use 2 or 3 egg whites and it will be a little airier.
I always use frozen strawberries (unsweetened) to save time and work. I thaw a 16-ounce bag and just dump the whole thing in, juice and all. No need to slice them as the whipping will break them up.
Depending on the power of your mixer and number of egg whites you use, you may have more filling than a 9x13 pan will accommodate. Darn! You'll be forced to do some quality control!