A poppy-seed torte, also called a Mohntorte, is flavored by poppy seeds and ground walnuts.
Preheat oven to 350 degrees. Butter a 7-inch springform pan. Line the bottom with parchment paper; butter parchment, and dust with flour, tapping out excess. In a small bowl, combine poppy seeds, walnuts, flour, almond extract, and salt.
In the bowl of an electric mixer fitted with the whisk attachment, beat egg yolks and 1/4 cup sugar on medium-high speed until pale and thick, about 3 minutes. Transfer to a large mixing bowl. Add the poppy-seed mixture, but do not stir in.
Place egg whites in a heatproof mixer bowl set over a pan of simmering water until warm to the touch. Attach bowl to mixer fitted with a clean, dry whisk attachment, and beat on high speed until soft peaks form. Beat in remaining 1/4 cup sugar until stiff and glossy peaks form. Fold egg whites into egg-yolk mixture in three batches.
Spread batter evenly in prepared pan, and bake until lightly golden and firm on top, about 30 minutes. Transfer to a wire rack to cool completely. Carefully remove sides of pan, and transfer torte to a serving plate. Dust with confectioners' sugar, and serve in wedges.