In a large mixing bowl, cream the butter and sugar until fluffy. Add the eggs, one at a time, mixing well. Stir in the milk, cream, white vinegar, and vanilla extract. Add flour, rye flour, cocoa powder, baking powder, and baking soda and mix to combine. Refrigerate for 30 minutes.
Preheat a heart-shaped waffle maker and cook the batter according to your model’s instructions.
Feel free to dust these with powdered sugar or perhaps a dollop of whipped cream or raspberry jam.