In a large mixing bowl beat the butter, eggs, sugar, and vanilla.
Add the flour, cocoa powder, and baking soda to a bowl and mix with a whisk.
Combine the egg mixture with the flour mixture and beat to combine.
Divide dough in half and wrap each half in plastic wrap and refrigerate for 1 hours.
Take the dough out of the refrigerator and roll out on a floured surface to 1/4 inch thick.
Cut the dough out into hearts with a 3-inch heart cookie cutter.
Place on a Silpat lined cookie sheet. Sprinkle with coarse sugar if desired.
Bake at 375 degrees for 8-9 minutes or until the edges are done and the top is set.
Let cool on a wire rack
To Make Frosting
Thaw the strawberries and puree. I like to use my hand blender for this.
Soften the butter or margarine and mix with the pureed strawberries.
Add one cup of powder sugar and beat to combine. Continue adding powdered sugar until the mixture reaches spreading consistency.
Once the cookies are cooled frost the bottom of one cookie with the strawberry frosting and then place another cookie on top to make a cookie sandwich.