Preheat oven to 350°F.
Grease (2) 9" round cake pans with butter. Line bottoms of pans with parchment paper, then lightly coat parchment with butter. Set aside.

In a medium bowl combine gf flour, baking soda, baking powder and salt; set aside.

In work-bowl of an electric mixer add sugar and butter; beat on low speed for about 1 minute. Increase speed to medium and continue to beat for 2 minutes. Scrape down sides of bowl and continue to beat for another 2 minutes until butter mixture is very soft.Scrape down sides of bowl again.

Add eggs and egg white, one at a time, beating well after each addition. Scrape down sides of bowl. Reduce speed to low and gradually add dry ingredients. Beat for about 30 seconds or until dry ingredients are completely incorporated.

Gradually add buttermilk; mixing on low speed for 30 seconds. Add sour cream and vanilla to batter and continue to beat for 30 seconds or until incorporated.
Pour batter into prepared pans; smoothing tops with a spatula.

Bake cakes in center of oven for
18-20 minutes or until a toothpick inserted into center of cakes comes out clean.

Remove cakes from oven and let cool in pans for 15 minutes. Invert cake layers onto
2 separate cake plates. Carefully peel away parchment paper from (now tops) of cakes.

Refrigerate cake layers for at least
30 minutes before proceeding with assembly of cake.

To assemble:
Remove cake layers from refrigerator and ice cream from freezer. Stir ice cream to make sure it is of equal consistency.

Turn over one of the cake layers and place, crust side up, in a clean 9" non-stick cake pan. Spoon 1/2 the ice cream on top of cake layer. Spread ice cream evenly over cake. Repeat this procedure with remaining ice cream and other cake layer.

Cover cake layers with plastic wrap and freeze for 8-10 hours or until ice cream is solid to touch.

Remove cake layers from freezer and discard plastic wrap. Using a paring knife, run blade around edge of one of the cake layers to separate it from pan.

Invert cake layer onto a plate, then turn it over onto another cake plate so that the ice cream layer is facing up.

Invert 2nd cake layer onto the 1st layer, again by running a knife around edges of pan to release cake.

The two ice cream layers should now be assembled one on top of the other. Press down gently so that the ice cream layers sort of seal together. Using a cake spatula, smooth sides of cake.

Return cake to freezer while you prepare frosting.

To make frosting:
In work-bowl of an electric mixer, fitted with a wire whisk, add cream and sugar. Mix on low speed to incorporate sugar, then increase speed to medium-high and continue to whisk for about 2 minutes or until stiff peaks form. Add vanilla extract and continue to whip for about 10-15 seconds or until incorporated.

To finish cake:
Remove ice cream cake from freezer.
Using a cake spatula, spread whipped cream frosting over sides and top of cake. Place fresh strawberries around outer edges of cake. Freeze for 1 hour before serving.

To slice: run blade of a sharp knife under hot water then wipe dry before slicing. Serve immediately.