Place the full-cream milk powder into a saucepan over low heat.

Stir continuously to prevent burning until it turns a deep, golden beige color with a rich, nutty aroma.

This process takes about 10 minutes. Remove from the heat and set aside.

Open the Medjool dates by hand and remove the pits.

Transfer the pitted dates to a food processor.

Add the melted butter, cardamom powder, and crushed mastic gum (if using).

Blend until a completely smooth paste forms.

Add the toasted milk powder to the mixture and process one more time until entirely homogeneous.

Place the date filling between two sheets of parchment paper.

Roll it out thinly into a uniform 10×15-inch / 25×38 cm rectangle.

Trim any uneven edges to form a perfect rectangle and set the trimmings aside. (Note: Save these trimmings to mix with leftover biscuits later to roll into delicious bite-sized balls!)

Peel off the top sheet of parchment paper.

Arrange the plain biscuits side-by-side in a single layer along the edge closest to you to form a horizontal row.

Lift the bottom parchment paper and roll the date sheet tightly over the biscuits until they are completely enclosed.

Place a second row of biscuits directly on top of the newly formed log.

Lift the parchment paper again and roll it forward to cover the new layer of biscuits.

Continue adding biscuit rows and rolling until the entire date rectangle is folded tightly around the layers.

Spread the white sesame seeds (or your favorite crushed nuts) evenly onto your countertop.

Gently roll the log over the seeds, pressing lightly so they adhere to the outside of the date paste.

Wrap the log securely and refrigerate for at least 1 hour to firm up.

Slice into equal rectangles using a sharp knife and serve alongside a warm cup of coffee or tea.