Preheat your oven to 360°F and line a baking sheet with parchment paper. In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt—this prevents lumps and ensures even distribution of leavening agents. In a separate large bowl, cream the softened butter and superfine sugar together for about 5 minutes until light and fluffy, which incorporates air for a tender crumb. Beat in the room-temperature egg until fully combined, then alternate adding the buttermilk and the dry ingredient mixture, starting and ending with the dry mixture—this prevents overmixing. Stir in the vanilla extract and red food coloring gel until the batter is evenly colored with a deep red-velvet tone.

Spread the red velvet batter into a thin, even 10-12 inch circle on your prepared baking sheet—thinner cakes bake more evenly and layer better in a trifle. Bake at 360°F for 10-12 minutes until a toothpick inserted in the center comes out clean; the cake should be tender, not dry. Transfer the baking sheet to a wire rack and let the cake cool completely, which takes about 15-20 minutes. Once cooled, you can cut the cake into circles or bite-sized pieces that will fit nicely into your trifle dish.

While the cake cools, prepare your trifle components. Toss the mixed berries (raspberries and strawberries) with the lemon zest in a bowl—the zest brightens the berry flavor and adds a subtle citrus note that complements the rich chocolate-vanilla cake. I like to let the berries macerate for 5-10 minutes so they release some of their juices, creating a natural berry syrup that will flavor each layer of the trifle. Have your custard sauce and lightly whipped heavy cream ready and at room temperature for easy layering.

Choose a trifle dish or large clear bowl (8-10 inch diameter works well) so you can see the beautiful layers. Begin by placing a layer of cooled red velvet cake pieces on the bottom, breaking them into bite-sized chunks—this creates an even base layer. Layer half of the macerated berries over the cake, then pour about half of the custard sauce over the berries, allowing it to soak into the cake and coat the layers. Add another layer of cake pieces, then top with the remaining berries and remaining custard sauce. I find that letting the trifle rest for 15-20 minutes at this point allows the flavors to meld and the cake to absorb the custard beautifully.

Top the entire trifle with the lightly whipped heavy cream, spreading or spooning it evenly across the surface for a gorgeous presentation. Garnish the top with fresh berries and some crumbled red velvet cake pieces for texture and visual appeal. Chill until ready to serve, or serve immediately if you prefer a slightly warmer trifle—both are delicious, though I prefer serving it chilled so the custard and cream maintain their silky texture.