Preheat the oven to 175 degrees Celsius.
Mortar the cardamom pods slightly, until you have broken them up into smaller pieces. No need to grind them into very fine powder. Set aside for later.
Cut the rhubarb into smaller pieces and set aside.
Combine oat flour, rice flour, potato starch, baking powder, baking soda and salt in a bowl.
Grease a mini muffin/bread loaf pan or line with parchment paper.
Add eggs and 2 tbsp of brown sugar to a bowl. Whisk just until slightly fluffy and combined (don't mix too much or until it becomes very fluffy). Remove 2 1/2 tablespoons of the egg and sugar mixture and set aside in a separate bowl.
Add the remaining brown sugar, sugar free granulated sugar, applesauce, yogurt/quark and milk to the batter and whisk until combined and smooth.
Add the dry ingredients to the bowl and stir until combined.
Divide the batter between the greased/lined muffin tins.
Take the bowl with the set aside egg and sugar mixture and add the remaining ingredients. Stir to combine. Spread the batter over the muffins (don't need to look perfect or cover all parts). Top with the diced rhubarb, slivered almonds and cardamom.
Place the muffin tins in the oven and bake for 15-20 minutes or until an inserted tooth stick comes out mostly clean.
Remove from the oven. Let them cool for 10-15 minutes, then remove gently from the muffin tins and place on a cooling rack.
Sprinkle with icing sugar on top just before serving (optional).