How to Make It
Stir together cherries, sugar, saba, vanilla, lemon zest and juice, and salt in a large saucepan. Cook over medium, stirring occasionally, until warmed through, about 10 minutes. Remove from heat, and cool completely, about 1 hour.
Preheat oven to 300°F. Grease and flour a 13- x 9-inch baking pan. Beat butter in bowl of a heavy-duty stand mixer on medium speed until light and creamy, about 5 minutes. Gradually add sugar and salt, beating on medium speed until pale and fluffy, about 4 minutes. Add eggs, one at a time, beating until combined after each addition. Add flour in 3 additions alternately with milk, beating on low speed until combined after each addition. Stir in vanilla. Pour batter into prepared pan, and smooth top with an offset spatula. Bake in preheated oven until golden brown and a wooden pick inserted in center comes out clean, about 1 hour. Cool in pan on a wire rack 20 minutes. Invert cake onto wire rack, and cool completely, about 1 hour. Cut cake into 1-inch pieces.
Beat heavy cream with a handheld mixer fitted with the whisk attachment on medium speed, gradually beating in 1/2 cup powdered sugar until soft peaks form, 3 to 4 minutes. Cover and chill. Combine cream cheese, honey, lemon zest, salt, and remaining 1/4 cup powdered sugar in bowl of a heavy-duty stand mixer fitted with the paddle attachment. Beat on medium speed until light and smooth, about 6 minutes, stopping to scrape down sides of bowl as needed. Add goat cheese, and beat on medium speed until smooth, about 1 minute. Add crème fraîche, and beat until incorporated, about 30 seconds. Fold 2 cups whipped cream into cream cheese mixture just until incorporated. Fold in another 2 cups whipped cream just until incorporated. Chill and reserve remaining 2 cups whipped cream.
Preheat oven to 300°F. Crumble 2 cups cake pieces over a rimmed baking sheet. Add melted butter and black pepper; toss to coat. Bake, stirring occasionally, until golden brown and dry, 25 to 30 minutes.
Drain cherries in saba, reserving juice. Reserve 1/4 cup drained cherries and 1 tablespoon juice for garnish. Layer one-third of untoasted cake pieces (about 4 cups) in a 4-quart trifle dish. Top with one-third of drained cherries (about 1 cup), and drizzle with one-third of juice (about 1/2 cup). Spread half of cheesecake filling (about 2 1/2 cups) over top. Sprinkle with 1/2 cup toasted cake crumbs. Layer with half of remaining untoasted cake pieces and half of remaining drained cherries; drizzle with half of remaining juice (about 1/2 cup). Spread remaining half of cheesecake filling over top. Top with remaining untoasted cake pieces and remaining drained cherries, and drizzle with remaining 1/2 cup juice. Spread reserved 2 cups whipped cream over top. Chill, uncovered, until cake has softened, about 2 hours. Garnish with reserved 1/4 cup drained cherries, black pepper, and, if desired, edible flowers and fresh fruit. Garnish with a sprinkle of the toasted cake crumbs, reserving remaining crumbs to garnish individual servings.