Preheat the oven to 350° F so it’s ready when you are.
Measure 160 grams of wheat berries and mill, or measure out about 1 1/3 cup of milled grain if you do not have a scale. Alternately, measure160 grams of conventional flour (about 1 1/2 cup) into a large bowl.
In the bowl of your stand mixer, or in a large bowl with traditional beaters, cream the softened butter and sugar until pale and fluffy.
Meanwhile, make the streusel topping so that the lemon can be zested before it will need to be cut and squeezed later.
Simply combine 2 tbsp of cold, shredded butter, the zest of 1 lemon, 2 tbsp of flour (any kind) and 4 tbsp of turbinado sugar in a small bowl, stirring and pressing with a fork until it looks a bit like sand and pebbles, then set back in the fridge until needed.
Once the butter and sugar have whipped together in the standing mixer, add two eggs and mix them in well. Follow up with 1/2 cup of sour cream, the juice of 1/2 lemon and 1/3 to 1/2 cup of sour dough discard, if using. Be sure to scrape down the sides of the mixing bowl.
Reduce the speed to low - or simply mix by hand a this point - and add in the flour mixture a little at the time, stirring only as much as is necessary.
Gently fold in 1 to 2 cups of berries with a spatula while scraping down the sides of the bowl.
Drop equal sized portions of batter into a lined muffin pan. The batter will be thick. This is typically enough to make one dozen standard sized muffins.
Do your best to equally distribute your streusel topping onto each of the muffins. Save yourself the frustration and just use your fingers.
Bake at 350F for 25 minutes. It might be a good idea to check at 20 minutes, inserting a fork to see if it comes out clean. (Be sure to insert your fork on the side though, not through the streusel topping, as it will stick to the fork and give you an “inaccurate reading”).
Pour a glass of milk and enjoy!