First Step: Prepare Strawberry Reduction Simmer the strawberry puree over medium-low heat until it reduces by half and thickens to concentrate flavor. Let cool completely, reserving part for frostings. This intensifies the natural sweetness and bright color for the strawberry cake layer and frosting.

Second Step: Prepare Cake Layers Preheat oven to 350°F (175°C). Grease and line three 8-inch cake pans with parchment. In a bowl, sift together flour, baking powder, and salt to ensure even texture and avoid lumps.

Third Step: Cream Butter and Wet Mixture In a mixer, beat butter, vegetable oil, granulated sugar, and half of the vanilla extract until the mixture is light and fluffy. Add eggs one by one, blending well after each addition to incorporate air and provide structure.

Fourth Step: Combine Dry and Wet Ingredients Alternate adding the dry flour mixture and milk to the creamed mixture, beginning and ending with flour. Mix gently to prevent overdevelopment of gluten, ensuring tender crumb layers.

Fifth Step: Divide and Flavor Batter Split the batter into three equal parts by weight:

• Strawberry Layer: Fold in the cooled strawberry reduction, strawberry extract, optional red food coloring, and 2 tablespoons of flour for stability.
• Vanilla Layer: Add the remaining vanilla extract and 2 tablespoons flour.
• Chocolate Layer: Melt chopped chocolate, combine with cocoa powder, and fold into the last portion.

Sixth Step: Bake and Cool Layers Distribute each batter into its prepared pan. Bake for 25-30 minutes or until a toothpick inserted in the center comes out with a few moist crumbs. Cool layers completely and trim domed tops for even stacking.

Seventh Step: Prepare Frostings Chocolate Buttercream: Beat butter until soft. Add half powdered sugar, then cocoa powder, vanilla, and cream. Mix smooth, add remaining sugar with additional cream/water to desired consistency, and a pinch of salt. Vanilla Buttercream: Beat butter, add half powdered sugar, vanilla, and cream. Add remaining sugar and salt, mixing to smooth consistency. Strawberry Buttercream: Fold strawberry reduction and extract into a portion of vanilla buttercream, adding salt to balance.

Eighth Step: Assemble Cake Place the chocolate layer on a serving board; spread chocolate buttercream evenly. Add strawberry layer and spread strawberry buttercream. Top with vanilla layer, spreading vanilla buttercream evenly.

Ninth Step: Frost Sides Apply each corresponding frosting color vertically along the cake sides, aligning with the layers, and smooth carefully to keep clean stripes without mixing.

Tenth Step: Prepare Ganache Drip Heat heavy cream to a boil, pour over chopped chocolate chips, let sit 2 minutes, then whisk until smooth. Cool slightly until thick but pourable for dripping.

Final Step: Drip and Decorate Drizzle ganache drops around the cake edges using a squeeze bottle or spoon. Pipe decorative vanilla buttercream swirls on top and garnish with fresh strawberries for a stunning finish. Chill for at least 30 minutes before serving.