Preheat the oven to 350°F (180°C). Line baking sheets with parchment paper.
Place the flour, baking powder, tahini, sugar, and softened butter in a large bowl. Mix with your hands until a soft, uniform dough forms. It should feel slightly oily and hold together when shaped. If it is too crumbly, mix in an extra tablespoon of tahini.
If using skin-on almonds, cover them with boiling water and leave for 5 minutes. Drain, let cool enough to handle, slip off the skins, and pat dry. Skip this step for ready-blanched almonds.
Divide the dough into 35–40 portions and roll into walnut-sized balls. Arrange on the prepared baking sheets with space between them. Gently press one almond into the center of each ball.
Bake for 20–25 minutes, until the bottoms are golden and the tops are lightly colored. Do not overbake: the cookies will firm up as they cool.
Let the cookies cool completely on the baking sheets before moving them. They are very fragile while warm.