Navigating the science behind what's best to feed your child can be difficult, but the research linking essential fatty acids (EFAs) to neural development in kids is a nutritional no-brainer. In wonky terms, EFAs are the polyunsaturated fatty acids known as omega-3s and omega-6s, which play a vital role in cell-membrane renewal. They're "essential" because the body can't synthesize them on its own and must ingest them. The benefits of EFAs during growing years (especially up to age 3) are startling: They enhance cognitive, aural, and optic development; help control aggressive behavior; and reduce the long-term risk of depression and mental illness. Omega-6s, found in cereals and vegetable oils, are easy to work into your child's diet, but omega-3s tend to be trickier. Fish, flaxseed, pumpkin and sunflower seeds, all eggs, and leafy greens are good sources—but that doesn't mean they fall into your kid's favorite food group. Cookie is here to help with a classic egg custard, a riff on salmon sushi (no rolling required), and nutty flaxseed crackers that will make you excited for snack time, too.

Easy Egg Custard

This classic dessert remains a standout for its sophisticated yet mild flavor and its creamy texture. Ideally sized for a kids' snack but worldly enough for a dinner party, it takes just 15 minutes of prep time and can be stored in the refrigerator, covered, for up to 3 days. (It's even better the afternoon after you've made it.)

• 2 cups whole milk
• 2 eggs (preferably free-range)
• 2 egg yolks
• 1/3 cup sugar
• 1 teaspoon vanilla extract
• Freshly grated or ground nutmeg

1. Preheat oven to 300° F.
2. Place six 4-ounce ovenproof cups (you can use ramekins, or coffee cups marked as oven-safe) in a deep baking pan just large enough to hold them.
3. In a medium saucepan, bring the milk to a simmer over medium-low heat.
4. Meanwhile, in a separate bowl, whisk together the eggs, yolks, sugar, and vanilla.
5. Slowly pour the egg mixture into the simmering milk, whisking gently to combine.
6. Pour the mixture through a fine strainer into the cups (if the strainer clogs, use a spoon to scrape it clean), then sprinkle lightly with the nutmeg.
7. Pour hot (not boiling) water into the pan until it reaches halfway up the sides of the cups.
8. Bake until the custard is just set (it can still be a little loose), 30 to 35 minutes.
9. Let the custard cool in the water bath for about 2 hours before serving.

Tip: Cold-water fish such as salmon, mackerel, and herring are the best source of omega-3s (Japan's seafood-rich diet has been linked to that nation's life expectancy, among the world's highest at 82.5 years). In addition, "consuming EFAs may help prevent disorders like ADHD in kids and Alzheimer's in adults," says nutritionist Keri Glassman, who has created a nutrition snack bar for kids that contains omega-3s from flaxseed.

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