Baking Step:

1. For the crumble, put all ingredients together and mix well. It is not necessary to form a dough.
2. Refrigerate until firm and crumbly.
3. For the muffin, using a paddle attachment, mix the egg, milk, and oil at low speed for 1 minute.
4. Scrape down the bowl and add the muffin mix, butter, and salt. Mix for another 2 minutes at medium speed.
5. Deposit the batter into paper cups or muffin molds until 1/3 full. For standard muffins, the batter weight should be about 70g, and for jumbo muffins, it should be about 90g-100g.
6. Sprinkle the crumble on top of the muffin batter.
7. Bake at 180°C for about 30 to 35 minutes. Baking conditions may vary depending on batter weight and oven characteristics.
8. After about 20 minutes of baking, place the Biscoff biscuits on top of the muffins.
9. Continue baking in the oven.
10. Remove from the oven and let cool before serving.