Danish Layer Cake (Dansk Lagekage)

To make the pastry cream:

1. In a medium non-aluminum saucepan over medium heat, warm milk until tiny bubbles appear on the surface, about 6 to 8 minutes (about 180 degrees Fahrenheit/82 degrees Celsius).
2. Meanwhile, In a large bowl, whisk together egg yolks and sugar. Whisk in cornstarch and salt.
3. While whisking constantly, pour in half of the hot milk. Whisk in remaining hot milk and return to saucepan.
4. Cook over medium heat, whisking constantly, until the mixture thickens to a firm consistency, about 5 to 8 minutes. Whisk in vanilla. Scrape in to a bowl.
5. Cover with plastic wrap, pressing it directly on to the surface of the pastry cream. Refrigerate until chilled, about 2 to 3 hours. (Note: You will have just over 2 cups of pastry cream and you only need about 1 1/2 cups for this recipe.)

To make the cake:

1. Preheat oven to 350 degrees. Grease and flour 2 (8-inch) round cake pans, then line parchment paper. In a small bowl, whisk together milk, eggs, and vanilla. Set aside.
2. In the bowl of a stand mixer fit with the whisk attachment, beat together flour, sugar, baking powder, and salt. 
3. With the mixer on medium-low speed, beat the butter in to the flour mixture one piece at a time. Continue beating until the mixture resembles moist crumbs, 1 to 3 minutes total.
4. Add the milk mixture to the mixer and beat until light and fluffy, 1 to 3 minutes longer. Stir by hand with a rubber spatula to make sure the batter is fully combined.
5. Divide the batter evenly between both pans, gently tapping the pans on the counter to settle the batter. Bake until a toothpick inserted in the center of the cake comes out dry with a few crumbs attached, 20 to 25 minutes. Rotate the pans halfway through baking time.
6. Cool the cakes in the pans for 10 minutes. Run a small sharp knife around the inside of each pan to loosen, then flip the cakes on to a wire rack. Peel off the parchment paper, then flip the cakes right side up to cool completely, about 2 hours.

To make the frosting:

1. In a stand mixer fit with the paddle attachment, cream butter until pale and fluffy, about 3 minutes.
2. Reduce mixer speed to low. Add 4 cups powdered sugar, cream, vanilla, and salt (if using). Continue mixing 2 to 3 minutes longer. If the frosting seems too soft, add the remaining powdered sugar 2 tablespoons at a time.
3. Cover and refrigerate the frosting until assembling the cake, up to 1 week in advance.

To assemble the cake:

1. Slice off any domed tops of your cake to ensure they are flat. Cut each cooled cake in half lengthwise so there are four layers of cake total.
2. Cover the edges of a cake platter with strips of parchment paper to help keep it clean. Slide the pieces of parchment out from under the cake once the frosting job is done.
3. Dollop a small amount of frosting in the center of the platter to help anchor the bottom of the cake to the platter (so it doesn't slide around as you frost it).
4. Add one layer of cake to the serving platter. Add 3/4 cup of the pastry cream to the center of the cake and spread in an even layer to the edge. Align a second layer of cake over the first and top with 1 cup raspberry jam, spreading in an even layer to the edge.
5. Add a third layer of cake and top with 3/4 cup of pastry cream in the center, spreading in an even layer to the edge. Top with the last layer of cake. Brush away any large crumbs, dollop frosting in the center, and spread lightly to the edges.
6. To frost the sides, gather a few tablespoons of frosting on to the tip of the spatula, then gently spread it onto the side of the cake. Use gentle motions and don't press too hard or you will end up with crumbs in the frosting. Clean the spatula as needed.
7. Gently run the edge of the spatula around the sides to smooth out any bumps and tidy the area where the frosting merges between the sides and the top.
8. Decorate the cake as desired with more frosting or some fresh raspberries. Store leftovers in the refrigerator.