Grease a ceramic or glass soup bowl/cereal bowl with a thin layer of vegetable oil (about 1/2 tsp). Set aside.
In a mixing bowl, combine milk, cornstarch, sugar, and egg yolks. Stir well. Optionally, add 4 tbsp of freeze-dried strawberry powder to the mixture.
Set a fine mesh strainer over a nonstick pan and pour the mixture through the strainer. Optionally, add a slice of cheese to the pan.
Bring the mixture to a boil over medium-high heat, stirring continuously. Reduce the heat to medium-low and continue stirring with a spatula for 10 to 15 minutes, or until the mixture thickens to a consistency slightly thicker than Greek yogurt.
Transfer the mixture to the greased bowl and let it cool to room temperature. Cover the surface of the mixture with plastic wrap, ensuring it touches the surface to prevent a dry skin from forming. Chill in the refrigerator for at least 4 hours, or until the milk cake is fully set.
Once the milk cake has solidified, discard the plastic wrap. Place a serving plate upside down on top of the bowl. Carefully invert the cake onto the serving plate and gently tap or shake it until it releases and rests on the plate. Slice the cake into 6 to 8 individual pieces.
To serve the cake chilled, sprinkle shredded coconut or freeze-dried strawberry powder over the top. Decorate with fresh strawberries and serve chilled.
To serve the cake hot, preheat the oven to 400°F. Line a baking sheet with foil or parchment paper and arrange the cake slices on the sheet, leaving space between each slice. Apply a thin layer of egg yolk onto the surface of each cake slice. Bake at 400°F for about 20 minutes, or until the slices achieve a golden color.