In a medium saucepan over medium-low heat, combine heavy cream, dark chocolate, and honey. Stir gently until smooth, about 5–7 minutes. Whisk in cocoa powder and Kahlua. Pour into wine glasses and refrigerate for 2-3 hours to set.

Dissolve gelatin powder in warm whole milk in a bowl over simmering water. In another saucepan, combine remaining milk, heavy cream, instant espresso, and brown sugar. Heat until it simmers, remove from heat, stir in gelatin and vanilla. Cool before pouring over the chocolate layer. Refrigerate for at least 4 hours.

Prepare chocolate ganache by heating equal parts heavy cream and dark chocolate until smooth. Cool slightly until thickened but pourable.

Whip together mascarpone cheese, heavy cream, powdered sugar, and vanilla extract until medium peaks form.

Pour ganache over set panna cotta, dollop or pipe whipped mascarpone on top, and garnish with coffee beans. Serve chilled.