Preheat the oven to 350°F. Line a 12x17-inch cake pan with parchment paper. Set aside.
Cream butter and sugar with a paddle attachment in a stand mixer for 4 to 5 minutes on medium-high speed until light and fluffy.
While butter and sugar are creaming, whisk together the dry ingredients.
Beat in the eggs one at a time. Scrape the sides of the bowl after each addition and then add the vanilla extract.
Add sour cream and vegetable oil and mix until combined.
Alternate adding the dry ingredients with the buttermilk ⅓ at a time, beginning and ending with dry ingredients. Do not over mix!
Spread the batter into the pan and bake for 15 to 20 minutes. Check at 15 minutes. Allow the cake to cool while you slice the strawberries in half and prepare the icing.
For the icing, mix the cream cheese and butter on medium-high speed for 1 minute with the whisk attachment.
Add sugar all at once and turn the mixer on low to combine. Once combined, add cream, salt, and almond extract, and mix on medium-high speed for 4 to 5 minutes.
Ice cake and decorate with strawberries and blueberries. Use a star icing tip to pipe stars in between blueberries. Pipe a shell border around the cake to finish the edges if you wish.