In a separate medium bowl whisk the eggs lightly, then add ricotta, milk (or buttermilk), the 3 tablespoons milk, melted butter, lemon zest, lemon juice and vanilla extract. Whisk until mostly smooth; small lumps of ricotta are fine.

Combine batter

Pour the wet mixture into the dry ingredients and gently fold with a rubber spatula until just combined. Do not overmix; a slightly lumpy batter yields tender pancakes. Fold in the 1 cup fresh blueberries, reserving a few for topping.

Rest batter

Let the batter rest 10 minutes at room temperature. This relaxes the gluten and allows baking powder to begin activating, producing fluffier pancakes.

Heat griddle

Place a heavy skillet or griddle over medium heat and brush or melt about 1 tablespoon butter to coat. Heat until a drop of water sizzles and evaporates on contact (about 325–350°F / 160–175°C on an electric griddle).

Cook pancakes

Use a 1/4-cup measuring cup to pour batter onto the hot griddle, leaving 2 inches between pancakes. Cook until bubbles form on the surface and edges look set, about 2–3 minutes. Flip and cook the second side 1.5–2 minutes, until golden and cooked through. Transfer to a warm oven (200°F/95°C) while you cook remaining batter. Re-butter griddle as needed.

Lemon custard (topping)

Heat lemon juice

In a small heavy saucepan, combine the lemon juice and 1 cup granulated sugar. Warm gently over low heat just until sugar dissolves and the mixture is warm; do not boil.

Temper yolks

Whisk the 3 egg yolks in a heatproof bowl. While whisking constantly, slowly pour about 1/3 of the warm lemon-sugar mixture into the yolks to temper them. Continue whisking and slowly add another 1/3, then the remaining.

Cook custard

Pour the tempered yolk mixture back into the saucepan and cook over low heat, stirring constantly with a wooden spoon or heatproof spatula, until the mixture thickens and coats the back of the spoon (175–180°F / 80–82°C), about 4–6 minutes. Do not boil.

Finish custard

Remove from heat and whisk in the cold butter pieces, one or two at a time, until fully incorporated and the custard is smooth and glossy. Stir in the lemon zest and a 1/4 teaspoon pinch of salt. Strain through a fine mesh sieve into a clean container to remove any cooked bits for an extra-silky texture. Cover surface with plastic wrap to prevent skin and let cool slightly; custard will thicken as it cools.

To finish & serve

Assemble

Stack pancakes (2–3 per serving) on warmed plates. Spoon 2–3 tablespoons of the warm (or room-temperature) lemon custard over the stack, allowing some to drizzle down the sides. Top with reserved fresh blueberries and a light dusting of powdered sugar, if using.

Optional syrup

Serve with maple syrup on the side for guests who want extra sweetness; the lemon custard is already tart and sweet, so syrup is optional.

Serve immediately

Serve pancakes immediately while warm. Leftover lemon custard can be refrigerated in a sealed container for up to 4 days; rewarm gently before serving.