Using the metal blade in your food processor: Place ricotta cheese, butter, flour, egg yolks, sugar, lemon peel and salt into work bowl. Process to blend well, scraping down work bowl once, about 30 seconds. Transfer contents of work bowl to large bowl. Beat egg whites in medium bowl to medium peaks. Fold egg whites into cheese mixture in two steps, the first step being about 1/3 of the egg whites to "lighten" the cheese mixture and then fold in the remainder.

Heat griddle over medium heat. Add butter and cook until sizzling. Drop batter by heaping tablespoon, or use medium scoop, onto hot griddle. Cook pancakes until bottoms are brown, about 2 minutes. Turn and cook until second sides are brown, about 1 minute. Transfer pancakes to baking sheet and keep warm in pre-heated oven. Repeat with remaining pancake batter, buttering griddle as necessary. Serve pancakes with Raspberry Butter and warm maple syrup.

Boil raspberries, water and 1 tablespoon sugar in heavy small saucepan over medium heat until syrupy, stirring frequently, about 5 minutes. (Or to microwave: Cook raspberries and sugar, omitting water, in 1-quart microwave-safe uncovered bowl on high, until syrupy, about 4 minutes.) Strain berry mixture through sieve, pressing with back of spoon to remove seeds. Cool.

Using your food processor with a metal blade process raspberry mixture, butter, powdered sugar and liqueur until smooth, scraping down sides of work bowl as needed. Add lemon juice to taste. Transfer Raspberry butter to small ramekin. (Can be prepared 1 day ahead. Cover and chill. Bring to room temperature before using.)

Makes about 2/3 cup.