1. Reserve 4 raspberries for garnish. Place remaining berries in a large cocktail shaker. Add fresh lime juice and muddle firmly, twisting and pressing until berries are completely smashed and juices release.

2. Set a fine mesh strainer over a measuring cup. Pour muddled berry mixture through strainer and press with muddler or spoon to extract all juice. You need about 4 ounces of thick raspberry-lime juice. Discard seeds and pulp.

3. Rinse cocktail shaker if needed. Pour strained raspberry-lime juice back into shaker. Add tequila and Cointreau, then add half a cup of ice. Seal shaker tightly and shake vigorously for 30 seconds until mixture is ice cold and well combined.

4. Run a lime wedge around rim of two tall cocktail glasses to moisten. Dip rims into salt plate, twisting gently for even coating. Fill each glass with crushed ice or regular ice cubes.

5. Strain margarita mixture into prepared glasses, dividing evenly. Garnish each glass with 2 reserved raspberries and a lime slice. Serve immediately while cold and perfectly mixed.