5 tablespoons (75 grams) warm whole milk (105°F/41°C to 110°F/43°C)
2 teaspoons (6 grams) active dry yeast
1½ cups (300 grams) plus 3 tablespoons (36 grams) plus ¼ teaspoon (1 gram) granulated sugar, divided
1 cup (227 grams) Kerrygold unsalted butter, softened and divided
1½ teaspoons (4.5 grams) kosher salt, divided
3 cups (375 grams) all-purpose flour, divided
2 large eggs (100 grams), room temperature and divided
3½ teaspoons (14 grams) vanilla extract, divided
3 tablespoons (63 grams) unsulphured molasses
2 tablespoons (30 grams) water
1½ teaspoons (3 grams) ground ginger
1½ teaspoons (3 grams) ground cinnamon
⅛ teaspoon ground nutmeg
⅛ teaspoon ground allspice
⅛ teaspoon ground cloves
Garnish: confectioners’ sugar
Instructions
Butter a 13x9-inch baking pan. Line pan with parchment paper, letting excess extend over sides of pan.
In a small bowl, stir together warm milk, yeast, and ¼ teaspoon (1 gram) granulated sugar. Let stand until foamy, about 5 minutes.
In the bowl of a stand mixer fitted with the paddle attachment, beat ⅓ cup (76 grams) butter, 3 tablespoons (36 grams) granulated sugar, and 1 teaspoon (3 grams) salt at medium speed until creamy, 3 to 4 minutes, stopping to scrape sides of bowl. Add yeast mixture, 1¾ cups (219 grams) flour, 1 egg (50 grams), and ½ teaspoon (2 grams) vanilla; beat at low speed just until combined, 30 seconds to 1 minute, stopping to scrape sides of bowl. Increase mixer speed to medium, and beat until dough is well combined and elastic, 4 to 5 minutes, stopping to scrape sides of bowl. (Dough will be tacky but should not stick to hands.) Press dough into prepared pan in a thin layer. Cover loosely with plastic wrap, and let rise in a warm, draft-free place (75°F/24°C) until doubled in size, about 2 hours.
Preheat oven to 350°F (180°C).
Clean bowl of stand mixer and paddle attachment. Beat remaining ⅔ cup (151 grams) butter, remaining 1½ cups (300 grams) granulated sugar, and remaining ½ teaspoon (1.5 grams) salt at medium speed until fluffy, 4 to 5 minutes, stopping to scrape sides of bowl. Beat in remaining 1 egg (50 grams); scrape sides of bowl.
In a medium bowl, whisk together ginger, cinnamon, nutmeg, allspice, cloves, and remaining 1¼ cups (156 grams) flour. In a small bowl, whisk together molasses, 2 tablespoons (30 grams) water, and remaining 3 teaspoons (12 grams) vanilla. With mixer on low speed, gradually add ginger mixture to butter mixture alternately with molasses mixture, beginning and ending with ginger mixture, beating just until combined after each addition and stopping to scrape sides of bowl. Spread batter onto dough in pan.
Bake until top is set and edges are golden brown, 25 to 35 minutes. Let cool in pan for 15 minutes. Using excess parchment as handles, remove from pan. Serve warm or at room temperature. Garnish with confectioners’ sugar, if desired.
Recipe by Bake from Scratch at https://staging.bakefromscratch.com/gingerbread-st-louis-gooey-butter-cake/