Homemade Ice Cream Cake

My husband loves ice cream cakes and since ice cream cakes are so expensive, I googled "ice cream cake recipe" and discovered that we have been spending way too much money on buying ice cream cakes from Baskin Robbins.  I made a trial cake last week for my FIL's birthday.  The crust turned out too thick, I added chocolate turtle bits to the ice cream which made it too sweet, I only had a 9" spring form pan which made for slices that were too big, and I didn't put a layer of icing on it so it didn't look professional.  I modified my recipe (even bought a smaller spring form pan) and made this cake yesterday for my daughter's birthday and it turned out much better than last weekend's version so here's the recipe.

1 cup oreo crumbs
1/4 cup butter, melted
2L ice cream
1 cup heavy cream
2 tbsp icing sugar
1 tsp pure vanilla extract

1. Mix oreo crumbs with butter.  Press into bottom/sides of an 8" spring form pan.  
2. Bake at 350F for 6-8 minutes.  Allow to cool completely and put into the freezer.
3. Defrost the ice cream at room temperature for 30 minutes.  Next time I'm going to try to make my own ice cream to make it a real "homemade" ice cream cake. But for now, Kawartha's Moose Track ice cream (so yummy!) from Costco works just fine.
4. Scoop ice cream into the chilled pan with the crust.  Ensure ice cream is packed into the pan so there are no air pockets.  Put into freezer for at least 2 hours or overnight.  
5. Beat heavy cream, sugar, and vanilla until soft peaks.  
6. Take the cake out of the spring form pan.  Frost the cake on the top and sides and return to freezer for another 2 hours or overnight.  I don't think I beat this enough so the whipped cream became kind of soft when I started to frost the cake but after I froze it again, it was fine.  i'll have to work on making a stiffer whipped cream next time.
7. Write a message on the cake and decorate with some buttercream icing if you wish.
8. Defrost for 10 minutes at room temperature before serving.