In a small pot, stir together strawberries, granulated sugar, and water. Cook over medium-high heat, stirring occasionally, until it comes to a boil. Continue cooking until the mixture thickens.

Transfer the jam to a small bowl and let it cool completely in the fridge.

Preheat the oven to 350°F. Line the bottom of two 6" round cake pans with parchment paper.

In a medium bowl, whisk together flour, cocoa powder, baking powder, baking soda, and salt. Set aside.

In a large mixing bowl, whisk together melted butter, oil, granulated sugar, and brown sugar until combined. Add the eggs and whisk until smooth.

Alternate adding half of the flour mixture and then half of the milk, mixing until just combined after each addition.

Divide the batter evenly into the prepared cake pans. Smooth the surface with a spatula.

Bake for about 40-45 minutes or until a toothpick inserted comes out mostly clean with some crumbs attached.

Let the cakes cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.

In a large mixing bowl, beat softened butter until creamy. Add the cream cheese and continue beating until smooth.

Add the powdered sugar and beat on low speed until combined. Add the strawberry jam and vanilla extract, and mix until combined.

Use a serrated knife to level the cake layers and cut them in half to make four layers.

On a cake turntable, place the first cake layer and pipe a ring of frosting around the edge.

Add about 4 tablespoons of strawberry jam in the middle of the frosting ring and smooth it into an even layer. Add diced strawberries on top.

Repeat with the remaining cake layers and fillings.

Apply a thin layer of frosting to the cake as a crumb coat and scrape away the excess.

Apply a final coat of frosting and smooth it with a scraper. Decorate with halved strawberries on top.