Make the sauce: Combine butter, brown sugars, cream and salt in a medium saucepan on the stove-top over medium heat. Stir until butter melts and mixture comes to a boil. Boil for 4 minutes, or until the sauce coats the back of a spoon. Remove from heat. Add 3 Tbsp. sauce to each of 4 Meal Mugs. Place mugs in the freezer while you make the rest of the cakes. Set aside rest of sauce.
Make the cakes: Measure out 1 cup of dates, well packed, then remove to a cutting board and coarsely chop. Add to a medium bowl with the baking soda and boiling water. Set aside to stand while you make the cake batter.
In a medium bowl with an electric mixer or the bowl of a stand mixer with a beater blade, beat the butter with the brown sugars until creamy. Add eggs and beat until combined, scraping down sides of bowl as necessary. Add flour and baking powder, along with a pinch of salt. and mix until smooth. Add soaked dates together with the soaking water. Mix until combined. (Batter will be quite liquidy at this point).
Remove Mugs from freezer. Divide cake batter between 4 Meal Mugs and place on a baking sheet. Bake in preheated oven for about 35 minutes, or until a tester comes out clean. Remove from oven. Use a skewer to poke holes in the cakes, then pour the remaining sauce over-top, dividing it equally between the 4 mugs. Change oven setting to broil, with rack positioned so the tops of the mugs will be about 6 inches from the heat source. Return tray with mugs to oven under broiler and broil until sauce is bubbly. WATCH CLOSELY as this can easily burn. It will only take a short time, so don't take your eyes off them. Remove from oven, garnish with some pecan pieces, if desired and let stand a few minutes, to allow the sauce to cool a bit.
Enjoy warm with a scoop of ice cream, if desired.
Be sure to read the "Cook's Notes" in the original post, for more tips, options, substitutions and variations for this recipe!