Preheat your oven to 350°F (175°C). Prepare three 8-inch cake pans by buttering, flouring, and lining them with parchment paper. Set them aside.
Sift the cake flour, baking powder, and salt into a bowl. In a separate container, combine the vanilla extract with the milk and set both aside.
In a stand mixer or using a hand mixer set to medium speed, cream the butter and sugar together for about 5 minutes until light and fluffy.
Scrape down the sides of the bowl, then add the eggs one at a time. Allow each egg to fully incorporate, about 15 seconds, before adding the next. Scrape down the bowl again to ensure everything is evenly mixed.
Mix in the raspberry puree or jam until it is fully combined and the batter takes on a fruity aroma and slight color.
Reduce the mixer speed to low. Gradually add the dry ingredients in three parts, alternating with the wet milk mixture. Begin and end with the dry ingredients, mixing just until combined after each addition.
If desired, add a few drops of red food coloring for a richer raspberry hue,
Optional: Add in food coloring at this point.
Gently fold the batter with a spatula to ensure everything is evenly incorporated. Divide the batter evenly between the 3 prepared pans. Smooth the tops with a spatula.
Bake the cakes for 17–22 minutes, or until a toothpick inserted in the center comes out with a few crumbs. Keep an eye on them after 17 minutes. When your kitchen smells like cake, they’re likely close to done. Cool the cakes completely before frosting.