Frangipane-Jam Buns

• In the bowl of a stand mixer fitted with the paddle attachment, beat 1 cup (125 grams) flour, sugar, yeast, and salt at low speed until combined, about 30 seconds. Add warm milk, and beat just until combined. Add eggs and vanilla bean paste; beat at medium-low speed until combined, about 1 minute, stopping to scrape sides of bowl. With mixer on low speed, gradually add remaining 1½ cups (188 grams) flour, beating just until combined.
• Switch to the dough hook attachment. Beat at low speed until smooth and elastic, 6 to 8 minutes. (Dough will be on the stiffer side at this point.) Add butter, 1 tablespoon (14 grams) at a time, beating until combined after each addition, 6 to 8 minutes total, and stopping to scrape sides of bowl and dough hook. (Dough may look slightly broken during this process but will come together later.) Increase mixer speed to medium-low; beat until a smooth, elastic dough forms, about 6 minutes, stopping to scrape sides of bowl and dough hook. Turn out dough onto a clean surface, and knead 4 to 5 times. Shape dough into a smooth round.
• Spray a large bowl with cooking spray. Place dough in bowl, turning to grease top. Cover and let rise in a warm, draft-free place (75°F/24°C) until doubled in size, 1 to 1½ hours.
• Preheat oven to 350°F (180°C). Line 2 baking sheets with parchment paper.
• Punch down dough; cover and let stand for 5 minutes. Turn out onto a clean surface, and divide into 12 portions (about 50 grams each). Shape 1 portion into a smooth ball, pinching any seams to seal. (Keep remaining dough covered with plastic wrap to prevent it from drying out.) Repeat procedure with remaining dough. Press or roll each dough ball into a 3½-inch circle, and place 1½ to 2 inches apart on prepared pans. (Dough rounds may shrink slightly.) Cover and let rise in a warm, draft-free place (75°F/24°C) until puffed and dough holds an indentation when poked, 30 to 40 minutes.
• Using a floured ¼-cup glass jar, make a 2¼-inch-wide, ¼- to ½-inch-deep well in center of each dough circle. (See PRO TIP.) Place 1 tablespoon (about 17 grams) Hazelnut-Almond Frangipane into each well, pressing to completely and evenly fill.
• In a small bowl, whisk jam until smooth. Spoon about 1 teaspoon (6 grams) jam in center of frangipane on each bun, gently spreading into a circle as desired.
• In another small bowl, whisk together egg yolk and 1 teaspoon (5 grams) water. Brush dough with egg wash. Crumble Vanilla Streusel over buns.
• Bake until golden brown and an instant-read thermometer inserted in center of bun registers 190°F (88°C), 10 to 14 minutes. Serve warm or at room temperature.

Hazelnut-Almond Frangipane

• In a medium bowl, stir together sugar and butter until well combined. Add almond flour and all remaining ingredients, stirring until well combined.

Vanilla Streusel

• In a medium bowl, stir together sugar, melted butter, vanilla bean paste, and salt. Stir in flour until well combined.