Old-Fashioned Crumb Cake

Directions

1. 1.

   Stir together yeast, 1/4 cup warm milk, and 1 tablespoon sugar in bowl of mixer until yeast is dissolved, then let stand until foamy, about 5 minutes. (If mixture doesn't foam, discard and start over with new yeast.)

2. 2.

   Stir together lemon juice and remaining 3/4 cup milk and let stand until curdled, 1 to 2 minutes.

3. 3.

   Add 3 3/4 cups flour to yeast mixture along with salt, eggs, vanilla, and remaining 1/2 cup sugar and mix at low speed until just combined. Add curdled milk and beat at medium speed until a dough forms. Add butter, 1 piece at a time, beating, then continue to beat until dough is silky and elastic, 5 to 8 minutes. (Dough will be very sticky.) Sprinkle with remaining 2 tablespoons flour and cover bowl with a clean kitchen towel (not terry cloth). Let dough rise in a draft-free place at warm room temperature until doubled in bulk, 1 1/2 to 2 hours.

4. 4.

   Pulse together topping ingredients in a food processor until many large clumps form. Transfer to a bowl and chill, covered, until ready to use.

5. 5.

   Butter a 13- by 9-inch baking dish or pan.

6. 6.

   Stir dough several times with a rubber scraper to release air, then spread evenly in baking dish.

7. 7.

   Sprinkle dough with half of topping, then cover dish with kitchen towel and let dough rise again in a draft-free place at warm room temperature until almost doubled in bulk, 1 to 1 1/2 hours.

8. 8.

   Put oven rack in middle of oven and preheat oven to 350°F.

9. 9.

   Sprinkle remaining topping over top of cake and bake until topping is golden, 55 to 60 minutes. Cool cake in pan on a rack until barely warm, then cut into squares.