1. Position a rack in the center of the oven and preheat to 400°F. Line a large baking sheet with parchment paper.

2. In a large bowl, whisk together the flour, sugar, baking powder, salt, and lemon zest.

3. Pour in the cold heavy cream and almond extract. Stir with a fork or spatula until a shaggy dough forms, then gently knead it two or three times in the bowl until it comes together.

4. Turn the dough out onto a lightly floured surface and divide it in half. Pat each half into a disk about 6 inches wide and 1 inch thick.

5. Cut each disk into 4 wedges and place the wedges on the baking sheet about 2 inches apart. Sprinkle the tops with sliced almonds.

6. Bake for about 25 minutes, until the scones are light golden brown.

7. Cool on a wire rack. Meanwhile, whisk the powdered sugar, 2 tablespoons of milk, vanilla, and lemon extract until smooth, adding more milk if needed.

8. Once the scones have cooled completely, brush or drizzle the glaze over them and let it set.