A bavarian is a rich custard-and-gelatin-based dessert. Any shaped small rum baba, flared baba, or dariole molds may be used to make it.
Rinse twelve 3 1/2-ounce baba molds with cool water (do not dry and bavarians will be easier to unmold); set aside. Pour boiling water over tea in small heatproof bowl. Let steep for 10 minutes. Squeeze out and discard bags. Cool tea in ice bath until room temperature. Remove tea from bath, sprinkle gelatin evenly over cooled tea. Set aside to soften.
In a large heatproof bowl, whisk together eggs and egg yolks. Gradually whisk in sugar. Whisk in lemon juice and lemon zest. Set bowl over pan of simmering water, and whisk constantly until mixture is pale yellow and thick, 5 to 8 minutes. When the whisk is lifted, the batter should leave a trail resembling a ribbon. Remove from simmering water; whisk about 1 minute to cool slightly.
Place the bowl of softened gelatin over the same simmering water. Heat gelatin, stirring, about 1 minute, until all the crystals have dissolved. Remove gelatin from the heat, and let cool for 2 minutes. Whisk into the lemon mixture.
Set bowl over ice; stir with rubber spatula until cool, but not starting to set, 2 to 4 minutes. (Mixture must be cool, or whipped cream will melt.) Remove from ice. Whip cream to soft peaks. Fold cream into lemon mixture.
Use a spoon to fill each mold, tapping mold down on counter occasionally to remove air bubbles. Cover with plastic, and chill at least 6 hours, or overnight. May be made 1 to 2 days ahead.
To unmold, dip each mold quickly into a bowl of hot water. Dry off mold with a kitchen towel. Carefully run a warm knife around inside to break air locks. Tap mold down sharply on plate or work surface to remove. Use a fine sieve to sprinkle tops of bavarians with ground pistachios. Pour vanilla custard sauce in a thin even layer on serving platter. Arrange with rasberry bavarians on platter.