Preheat oven to 350 degrees. Line 2 baking sheets with either parchment paper or silicon baking mats.

In a large bowl, with a wooden spoon, mix the Sunbutter with the brown sugar. Stir until well blended. Add the eggs, baking powder, lemon juice, and vanilla. Stir well. Pour the granulated sugar in a small bowl. Take 1 tablespoon of the dough and roll in a ball. Roll the dough ball in the sugar and place on prepared baking sheet about 1 ½ inches apart. Repeat with the rest of the dough.

Dip a flat bottomed glass or measuring cup in the sugar and press down gently on the balls to flatten them.

Bake for about 10 minutes. They should look puffed and cracked but not dry.

Remove from oven, let cool 5 minutes on the pan and then remove with a spatula to wire racks to cool completely.

While cookies are baking, make the filling.

Place chocolate chips in a small, heatproof bowl. In a small saucepan, heat the cream or coconut milk over medium heat until it just comes to a boil. Pour over the chocolate and let set for 5 minutes and then whisk together until the mixture is shiny and smooth. Let stand until cooled and thickened, about 30 minutes. Whisk again before using.

To assemble the sandwiches, spread about 1½ teaspoons of chocolate filling on the flat side of half the cookies. Top with the remaining cookies, the flat side of the cookies going onto the chocolate. Gently press the cookies together so that the filling spreads almost to the edge. Let the cookies set on rack for about 20 more minutes before serving to let the filling completely firm up.