Cream the butter and sugar. In a stand mixer fitted with the paddle, beat the butter and granulated sugar on medium until pale and fluffy, about 2 minutes.

Add the egg and extracts. Beat in the egg, vanilla, and almond extract until fully combined, scraping down the bowl as needed.

Add the dry ingredients. Whisk the flour, baking powder, and salt together in a separate bowl, then add to the mixer on low speed, mixing just until the dough comes together with no dry streaks.

Chill. Divide the dough in half, pat each half into a disk, wrap in plastic, and refrigerate for at least 1 hour (or up to 2 days). This keeps the cookies from spreading into puddles in the oven.

Roll and cut. Preheat the oven to 350°F (175°C) and line two baking sheets with parchment. Roll one disk of dough to ¼-inch thickness on a lightly floured surface and cut into rounds with the cookie cutter. Transfer to the prepared sheets, spacing 2 inches apart.

Bake. Bake for 9-11 minutes, until the edges are just barely set and the centers still look slightly underdone. These cookies firm up as they cool, and overbaking is the main way they lose their tenderness. Repeat with the second disk of dough.

Cool completely. Let the cookies cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool all the way before glazing.

Steep the hibiscus. While the cookies cool, pour the boiling water over the dried hibiscus flowers and let steep for 10 minutes. Strain, pressing the flowers to extract all the ruby-colored liquid, and let cool to room temperature.

Make the glaze. Whisk the powdered sugar with 2 tablespoons of the cooled hibiscus liquid, the rose water, and a pinch of salt until smooth and pourable. Add more hibiscus liquid, a teaspoon at a time, if the glaze is too thick to drizzle.

Glaze and set. Spoon or drizzle the glaze over the cooled cookies and let sit at room temperature for about 20 minutes, until the glaze sets to a matte finish.