Preheat & Prepare Pan Preheat oven to 350°F (175°C). Grease a 9×13-inch baking dish.
Make Cake BaseI n a medium bowl, combine yellow cake mix, melted butter, egg, and vanilla. Stir until dough forms. Press evenly into prepared dish.
Prepare Cinnamon Filling In a large bowl, beat cream cheese until smooth. Add eggs and vanilla, mixing until fully combined. Gradually blend in powdered sugar and melted butter. Stir in cinnamon and nutmeg.
Assemble & Bake Pour filling over cake base and spread evenly. Bake for 40–45 minutes, until edges are set but center remains slightly gooey.
Cool Before Glazing Let cake cool completely in the pan before adding glaze.
Make Lemon Glaze In a bowl, beat cream cheese until smooth. Add powdered sugar, lemon juice, and zest, mixing until creamy. Add milk gradually until pourable.
Glaze & Serve Drizzle glaze generously over cooled cake. Slice and enjoy.
