The type of black tea is Ceylon tea leaves. Make tea-flavored milk paste on the first day and cookies on the second day.

On day 1, make black tea flavored paste. Add boiling hot water to the black tea leaves, cover with cling wrap, and let it steep for a while. Pour milk into a small pot and warm over low heat for 2-3 minutes while stirring.

Turn off the heat, add the steeped tea leaves, place a lid and leave for 10 minutes. Strain it with a tea strainer. After straining, press the tea leaves with a spoon to squeeze out the tea liquid.

Lightly rinse the small pot with water and put the milk mixture back in it. Add granulated sugar and heat on medium heat while stirring for 20-25 minutes.

Heat it until it gets thickened enough to see the bottom of the pan. After Turning off the heat, continue stirring for a short time to prevent scorching. Put it out in a container and let it cool. After cooling, cover with cling wrap to prevent drying.

Day 2, make cookies. Soften unsalted butter at room temperature in advance. Finely chop the walnuts. Cream the butter until smooth (mayonnaise-like). Add powdered sugar in two parts and mix well each time.

Use an electric hand mixer to beat at low speed for 2-3 minutes until whitish. Add 40 g (1.4 oz) of the black tea flavored paste and mix with a spatula until smooth.

Add 4 drops of vanilla oil. Use an electric hand mixer to beat at low speed for about 2 minutes. It will be a little whitish.

Add ground almonds and black tea leaves. Use a spatula to mix well until smooth.

Sift cake flour, cinnamon, cardamom, and clove over the mixture. Please adjust the amount of cinnamon powder to your liking (0.5-1g). Fold it to mix until lumps form.

Add chopped walnuts and fold to mix. Spread cling wrap on a work surface. Place the dough on it. Fold one side of plastic wrap to cover the dough and press it to flatten.

Next, fold it in half and press. Repeat '' folding and pressing'' 4 times until smooth. Form it into a flat square, and seal it with cling wrap. Let it sit in a fridge for 1-3 hours.

Cut and divide into about 6g (0.2 oz) each. (If you don't use a kitchen scale, form the dough into round balls, 1.5 - 2 cm / 0.6 - 0.8 inches in diameter.) Roll between the palms of your hands to form a rounded ball. Arrange balls 1.5cm / 0.6-inch apart on a baking sheet.

Let it sit in a freezer for 30 minutes. In the meantime, preheat an oven to 190℃ / 374 F. Lower the oven to 170℃ / 338 F 30 minutes later, and bake for 17 minutes.

Let it cool for 15 minutes, and roll cookie balls in powdered sugar. At first, coat with generous powdered sugar, and leave them on a tray. Roll them to coat again after 5 minutes, and lightly brush the extra powder off the cookie balls. It's all done! (Please store them in a closed container.)