01 - Preheat oven to 350°F. Grease a 9x13-inch baking pan and line with parchment paper for easy removal.
02 - In a large bowl, combine the cake mix, eggs, oil, and milk. Beat until smooth and pour into the prepared pan.
03 - In a separate bowl, beat together the cream cheese and butter until fluffy. Add powdered sugar and vanilla; beat until smooth.
04 - Drop spoonfuls of the cheesecake mixture evenly over the cake batter. Gently swirl with a knife or spatula for a marbled effect.
05 - Dollop strawberry pie filling or preserves over the surface. Add the sliced fresh strawberries, distributing evenly. Swirl gently again for a dramatic pattern.
06 - Sprinkle white chocolate chips and sliced almonds (if using) on top.
07 - Bake for 45-50 minutes, or until the edges are golden and the center is mostly set (a little wobble is fine).
08 - Cool in the pan for at least 20 minutes before slicing and serving.