Add sugar to butter at room temperature and mix well, add yolks one at a time, add vanilla oil, and mix well. Measure the butter and yolk mixture in half and distribute.

In the butter divided into two parts, knead the mixture of cocoa powder and soft flour.

In the remaining butter, knead the mixture of soft flour and skimmed milk. The mixture of raw powder is lumped together and wrapped in plastic, and rest in the refrigerator for about 30 minutes.

Take out the dough that is finished, sprinkle a little bit of powder, push the plain dough with a rolling pin, put the chocolate dough on the plain dough little by little, push it closely with a rolling pin, and push it to a thickness of 0.5cm to dip it into a cookie cutter. (If you do it this way, you'll have a lot of chocolate dough, but the pattern comes out the prettiest. If you don't like the chocolate dough left, you can connect the chocolate and plain dough well and roll it with a rolling pin.)

After panning the dough with a cookie cutter, bake it in an oven preheated to 170 degrees for 10 to 15 minutes. It's much more real and pretty before it's baked.

I used a little chocolate dough to make it look pretty, so I only had a lot of chocolate dough left, so I took a picture of it separately and made a black cat.

The patterns are also different. Real cow cookies are done! To make it taste better, it's a little yellow because it's baked for a long time, but if you bake it for 10 minutes, the dough doesn't bake a lot, so the shape is prettier.