Apple Crisp with Vanilla Custard Sauce

Preheat oven to 375 degrees F. Grease 9\" X 13\" pan with soft butter.

Pile sliced apples into pan and sprinkle with sugar and lemon juice. Stir fruit gently, in dish. Once apples are evenly coated, spread them uniformly.

Combine flour, oats, sugar, brown sugar, cinnamon and salt in a large mixing bowl. Toss ingredients with your hands to mix them. Add unsalted butter pieces to dry ingredients and use your fingers to rub in the butter until you have pea-sized crumbs. At this point, none of the flour should be noticeable.

Mix in pecans or walnuts. Spread topping evenly over apples and press down gently with your palm. Bake on center rack for 45-50 minutes, until juice bubbles around edges and topping is golden brown.

If the top starts to get too brown, move crisp down one shelf. Transfer crisp to wire rack and cool for at least 15 minutes before serving.

For Vanilla Custard Sauce: Whisk together yolks and sugar in a mixing bowl. Bring cream just to a simmer in a medium-sized non-stick saucepan and promptly remove it from the heat. Stir hot cream into yolks, adding about 1/3 cup at a time.

Pour mixture back into the saucepan. Cook custard over medium-low heat without letting it boil, stirring continuously until it thickens to the consistency of heavy cream (about 7 minutes).

Watch the sauce carefully, because the change is subtle. Strain sauce through a fine-mesh strainer into a small bowl. Stir in vanilla extract. Let sauce cool to room temperature, then chill it, covered, until cold. It will keep for two-three days. Whisk it briefly just before drizzling it on the crisp.