Heat oven to 425°F. Line a baking sheet with parchment paper. This step matters because the date syrup can stick quickly once it starts caramelizing.

Place sliced sweet potatoes in a large bowl. Add olive oil, date syrup, brown sugar, salt, pepper, and thyme. Toss until every slice is lightly coated. The mixture should cling evenly without pooling at the bottom of the bowl.

Spread the slices in a single layer. Keep space between each piece. Overcrowding traps steam and prevents the edges from turning crisp and dark.

Bake for about 35 minutes. Halfway through, rotate the pan so the slices color evenly. The potatoes are ready when edges turn deeper in color and slightly crisp while the centers remain soft when pressed.

While the potatoes roast, mix cream cheese and sour cream in a bowl until smooth. The texture should be thick but spreadable with no lumps.

Transfer roasted sweet potatoes to a serving plate while still hot. Place the cream mixture beside them rather than on top to keep the edges intact.

Drizzle olive oil over the cream mixture and scatter scallions on top. Serve immediately while the contrast between roasted edges and soft centers is still present.