1. Set a rack at the middle level of the oven and preheat to 350 degrees.

2. For the cake batter, in a large mixing bowl, cream the butter until soft and light. Use a hand mixer set at medium speed or a heavy-duty mixer fitted with the paddle, if you have one. Gradually beat in the sugar and continue beating for about 5 minutes, until very light. Add the egg and continue beating until lighter. Add the yolks, one at a time, beating after each addition and scraping the bowl and the paddle occasionally. Beat in the lemon zest and vanilla. Sift the flour and baking powder together several times, then stir into the batter.

3. To make the topping, mix the flour, sugar, and cinnamon in a bowl. Melt the butter and stir it in evenly. Rub the mixture to coarse crumbs by hand.

4. Rinse, halve, and pit the apricots. Spread the batter evenly in the prepared pan. Arrange the apricot halves, leaving a margin of ½ inch around the edge, cut side up on the batter, but don’t press them in. Scatter the crumbs evenly over the apricots and the batter.

5. Bake the cake for 50 to 60 minutes, until the crumbs are well colored and the cake is firm and no longer liquid in the center.

6. Cool the cake in the pan, then run a knife around the edges to loosen it from the pan. Remove pan side and slide from base to a platter. Dust the cake lightly with the confectioners’ sugar.

VARIATIONS

PINEAPPLE CRUMB CAKE: Substitute 1 pineapple, peeled, cored, quartered in the length, and sliced, for the apricots, above. Arrange the pineapple slices in concentric circles and slightly overlapping on the cake batter.

PLUM CRUMB CAKE: This is perfect in the late summer and early fall when the first Italian or prune plums come to market. Substitute 12 prune plums, rinsed, halved, and pitted, for the apricots, above.