1. Cake: Combine milk, honey, and yeast in a liquid measuring cup, and let stand in a warm place until foamy, about 5 minutes. Combine milk mixture with flour, butter, and salt in the bowl of a stand mixer fitted with the dough hook. Mix together on high speed until mixture begins to form a ball and is smooth, about 4 minutes. Form dough into a ball using your hands. Place in a buttered bowl, and turn to coat. Cover with plastic wrap, and let rise in a warm place until doubled, 45 minutes to 1 hour 30 minutes. Punch down dough (but make and cool glaze first).

2. Glaze: After dough has risen 30 minutes, melt butter and honey in a small saucepan over medium heat. Stir in confectioners' sugar and salt until smooth. Stir in almonds until well coated. Let cool.

3. Preheat oven to 400 degrees. Butter an 8-inch square baking pan, and line with parchment, leaving a 2-inch overhang on 2 sides. Butter parchment. Roll out dough into a 7-inch square on a lightly floured surface. Transfer to pan, and press evenly into bottom of pan. Spread glaze over dough (if it has congealed, reheat slightly, but make sure it's not hot). Cover with plastic wrap, and let rise in a warm place until dough is almost doubled and does not spring back when pressed, about 20 minutes. Bake until golden brown, about 20 minutes, rotating once. Let cool in pan 20 minutes on a wire rack. Lift out of pan using parchment, and let cool completely on rack, about 2 hours.

4. Pastry cream: While cake is cooling, mix together granulated sugar, cornstarch, and salt. Place egg yolks in a medium bowl, then whisk sugar mixture into egg yolks until smooth. Meanwhile, bring milk and 3 tablespoons honey to a boil in a medium saucepan over high heat. Pour a small amount into egg mixture, whisking constantly. Gradually whisk remaining milk mixture into egg mixture; when thoroughly combined, pour back into pan. Cook over medium heat, whisking constantly, until mixture thickens and begins to boil; continue to cook and whisk until mixture is very thick, 3 to 4 minutes. Remove from heat, and whisk in butter and vanilla. Transfer pastry cream to a bowl, and cover surface with plastic wrap. Refrigerate until completely cold, at least 2 hours and up to overnight.

5. Whisk pastry cream in a medium bowl until smooth. Whisk heavy cream with remaining 2 tablespoons honey in a separate bowl until medium peaks form. Fold a third of pastry cream into whipped-cream mixture with a rubber spatula. Fold whipped cream mixture into remaining pastry cream in 2 additions.

6. Cut cake in half horizontally with a serrated knife. Spread pastry-cream mixture on bottom layer, leaving a 1-inch border. Place remaining cake half, almond side up, on top, and press gently to push cream out to the edges. Refrigerate until chilled through, at least 45 minutes and up to 3 hours. Slice with a serrated knife, and serve.