Preheat oven to 325°F. Line a 9×5 loaf pan with parchment.
Simmer strawberries with 1–2 tbsp erythritol and lemon juice; mash/blend slightly; cool.
Whisk almond flour, coconut flour, baking powder, and salt.
Beat butter and cream cheese until fluffy; add erythritol.
Add eggs one at a time, then vanilla and lemon zest.
Fold in dry ingredients alternately with heavy cream; add pecans if using.
Spoon 2/3 batter into pan, swirl half strawberry compote, top with remaining batter and swirl remaining compote.
Bake 50–60 minutes; tent foil if browning too fast.
Cool 15 minutes, remove from pan, and chill at least 2 hours before slicing.