1. Preheat your oven to 350°F and grease and flour a 9-inch round cake pan really well—or line the bottom with parchment paper for extra insurance.
2. In a medium bowl, whisk together the flour, baking powder, and salt. Set this aside—having it ready makes the dividing process smoother.
3. In a separate large bowl, cream the butter and sugar together until light and fluffy—about 3-4 minutes with a mixer. This step is crucial for texture, so don’t rush it.
4. Beat in those eggs, one at a time, making sure each one is fully incorporated before adding the next. Stir in the vanilla extract.
5. Now here’s the key: gradually mix in the flour mixture, alternating with the milk, until smooth batter forms. Start and end with flour (flour, milk, flour, milk, flour). Mix until just combined—the batter should be smooth and lovely.
6. Here’s the fun part! Pour about one-third of the batter into a separate bowl. Stir in the cocoa powder and chocolate chips until well combined—this is your chocolate layer.
7. From the remaining batter, scoop out half and put it in another bowl. Mix in the strawberry jam and a few drops of pink food coloring if you’re using it. The rest of the batter stays plain vanilla.
8. Now you have three bowls! Spoon the chocolate batter into your prepared cake pan first, spreading it somewhat evenly. Then add dollops of the strawberry batter on top, followed by dollops of the vanilla batter.
9. Here’s the important part: take a knife and gently swirl through the batters to create a marbled effect. Just 2-3 gentle swirls—don’t overmix or you’ll end up with muddy brown instead of pretty swirls!
10. Bake for 30-35 minutes, but start checking at 28 minutes. You want a toothpick inserted in the center to come out clean or with just a crumb or two—not wet batter.
11. Let the cake cool in the pan for 10 minutes (it needs this time to firm up), then carefully transfer to a wire rack to cool completely.
12. Slice and serve! The marbled pattern will be different in every slice, which is part of the fun.

Nutrition Information (Per Serving):

• Calories: 340
• Carbohydrates: 48g
• Protein: 5g
• Fat: 15g
• Fiber: 1g
• Sodium: 180mg
• Calcium: 75mg (8% DV)
• Iron: 1.8mg (10% DV)
• Potassium: 125mg (4% DV)

Three flavors means triple the happiness!

Notes:

• Don’t overmix the swirl—just 2-3 gentle passes with a knife is enough.
• Make sure each flavored batter has similar consistency for even distribution.
• The food coloring is totally optional—jam alone gives a peachy-pink color.
• Every oven runs differently, so trust your toothpick test over exact timing.
• Use good quality strawberry jam with visible fruit pieces for best flavor.

Storage Tips:

• Keep covered at room temperature for up to 3 days—it stays incredibly moist.
• Individual wrapped slices freeze beautifully for up to 3 months.
• Don’t refrigerate unless your kitchen is really warm—it dries out the cake.
• The marbled pattern stays beautiful even after storage.

Serving Suggestions:

• Classic Style: Serve plain or with a dusting of powdered sugar
• Ice Cream Style: Serve with vanilla ice cream to complete the neapolitan experience
• Fancy Pants: Top with whipped cream and fresh strawberries
• Birthday Style: Frost with vanilla buttercream and decorate with all three colors

Mix It Up (Recipe Variations):

• Neapolitan Layer Cake: Make three separate thin cakes and stack with frosting between layers
• Neapolitan Cupcakes: Use the same technique in a muffin tin for individual servings
• Neapolitan Bundt Cake: Layer batters carefully in a bundt pan for prettier swirls
• Neapolitan Cheesecake Swirl Cake: Add dollops of cream cheese throughout for richness

What Makes This Recipe Special:

This classic three-flavor combination originated in Italy but became an American ice cream staple. Creating all three flavors from a single base batter makes this nostalgic cake easier than it looks, while gentle swirling keeps each flavor distinct. Every slice reveals a different marbled pattern, delivering chocolate, vanilla, and strawberry harmony that makes everyone happy.