Combine the heavy cream and tea bags in a small saucepan. Place the pan over medium-low heat and warm gently, stirring occasionally, until bubbles just start to form around the edges of the cream, about 5 minutes. Simmer 3 minutes more and then turn off the heat.
Place the chopped chocolate and salt in a medium bowl. Strain the hot cream mixture through a fine-mesh strainer over the chocolate and let sit for 3 minutes. Slowly whisk the now-melted chocolate into the cream, starting with small circles in the center of the bowl and moving into larger circles as the mixture begins to come together; stop when smooth and completely blended. Press a piece of plastic wrap directly on top of the ganache and refrigerate for about 3 hours, or until just set and cold but still pliable.
Place the cocoa powder in a shallow bowl. With a 1-ounce scoop, scoop level rounds of the ganache into your palm and gently roll into a ball. Roll the truffles in the cocoa powder to coat, then place in an airtight container and refrigerate until ready to serve.
Just before serving, sift a touch of gold dust, if using, over the top of the truffles for sparkle.