If you put all of the streusel ingredients into a bowl and chill (cut the butter into 1 cm cubes), it will be easier to work with.
Make the streusel. Put all of the ingredients into a bowl and rub together until crumbly. Once done, put into the freezer.
If making extra, using a food processor is very convenient (put the ingredients into the compartment and chill, then agitate in intervals rather than one steady blend).
Make the bread dough and let it rise the first time (until it doubles in size).
Making the custard.Combine the flour and cornstarch and sift.
Put the egg yolk, sugar, and sifted flours in a heat-resistant bowl.
Use a whisk to mix together.
Gradually pour in the milk as you stir so that no lumps form.
The sifting in Step 5 will make the cream nice and smooth.
Microwave for 2 1/2-3 minutes. During that time, take it out once to stir.
Add the butter and mix it in quickly. Cover the surface with plastic wrap and chill. (Cover tightly to prevent condensation).
Once chilled, add the vanilla essence and use a rubber spatula to stir until smooth.
After the bread dough has risen the first time, divide it in half and punch out the gas. Form into round balls and let sit for 20 minutes.
Lightly push out the gas and then use a rolling pin to roll the dough out into 20 x 25 cm rectangles. Spread half of the custard on each.
Roll up the dough as if rolling a sushi roll. Tightly close the seams.
Cut into 4 portions and place in a parchment paper lined pan (with the cut cross-section facing up).
Let rise a second time until they rise about 1 cm above the edge of the pan (you can use the oven's bread proofing function set at 40°C. In the summer, leave out at room temperature).
Spread the surfaces with milk and then sprinkle with the streusel. Bake for 20-25 minutes in an oven preheated to 180°C.
You can also make these in a 20 cm cake pan.
I made them with the same recipe (with double the amount of custard cream) Recipe ID: 1113833.
The shape of these is the same as this Gratin Bread Recipe ID: 1010545
I made these in muffin cups. Custard & Apple Version. Recipe ID: 984636.
Story Behind this Recipe
I made a large loaf of bread with custard cream.
Streusel is convenient to use as a topping for muffins, cake, sweet breads etc. When you make a chiffon cake and have egg yolks left over, use it to make this custard cream, so that you don't waste any part of the egg. The pound cake pans are 20 x 8 cm (height 6 cm).